Treatment of Luteal Phase Defects in Assisted Reproduction

Send Orders of Reprints at [email protected]

Current Drug Targets, 2013, 14, 000-000 1

1389-4501/13 $58.00+.00 © 2013 Bentham Science Publishers

Treatment of Luteal Phase Defects in Assisted Reproduction

Elkin Muñoz1,*

, Esther Taboas1, Susana Portela

1, Jesús Aguilar

1, Iria Fernandez

1, Luis Muñoz

2 and

Ernesto Bosch3

1IVI Vigo, Vigo Spain. Reproductive Medicine Unit;

2Hospital San José. Intensive Care Unit. Bogotá Colômbia;

3Instituto Valenciano de Infertilidad, Valencia University, Valencia Spain

Abstract: Abnormal luteal function is a common issue in assisted reproduction techniques associated with ovarian stimu-

lation probably due to low levels of LH in the middle and in the late luteal phase. This defect seems to be associated with

supraphysiological steroid levels at the end of follicular phase. The luteal phase insufficiency has not got a diagnostic test

which has proven reliable in a clinical setting. Luteal phase after ovarian stimulation becomes shorter and insufficient, re-

sulting in lower pregnancy rates. Luteal phase support with progesterone or hCG improves pregnancy outcomes and no

differences are found among different routes of administration. However, hCG increases the risk of ovarian hyperstimula-

tion syndrome. In relation to the length of luteal support, the day of starting it remains controversial and it does not seem

necessary to continue once a pregnancy has been established. After GnRHa triggering ovulation, intensive luteal support

or hCG bolus can overcome the defect in luteal phase, but more studies are needed to show the LH utility as support.

Keywords: Assisted reproduction treatments, luteal phase support, progesterone, hCG, LH, GnRH agonist triggering.

INTRODUCTION

The luteal phase is defined as the period of time between ovulation and the onset of menstruation, or until the estab-lishment of early pregnancy. It depends on the normal func-tion of a corpus luteum which secretes steroid hormones including estradiol (E2) and progesterone (P4) [1]. However, in the setting of assisted reproduction techniques where the ovarian function is modified by the use of gonadotropins and GnRH analogues [agonist (GnRHa) or antagonist (GnRHant)] in order to achieve controlled ovarian stimula-tion, the steroid production is deficient during the luteal phase [2].

Clinicians have used different regimens to compensate those luteal defects including progesterone, hCG, estrogen, GnRHa or LH [3] and there is a plethora of trials being ad-dressed to evaluate different drugs, doses or routes of ad-ministration with conflicting results [4]. Although there is a consensus on some topics of luteal support, there are still some other very controversial issues.

We describe the inadequate luteal function, the mecha-nisms considered as the origin of luteal defects in cycles of in vitro fertilization (IVF) and different regimens used as support of the luteal phase. We also consider new methods to support the luteal phase, with particular emphasis after trig-gering ovulation with GnRHa. Finally, we describe the length of support of the luteal phase.

INADEQUATE LUTEAL FUNCTION

The human luteal phase begins on the day of the rupture of the preovulatory follicle. This depends on the steroids

*Address correspondence to this author at the IVI VIGO, Plaza Francisco

Fernández de Riego 7, 36203. Vigo, Pontevedra Spain; Tel: +34

986021860; Fax: +34 986021869; E-mail: [email protected]

produced by the luteinized granulosa cells, the theca-lutein cells and surrounding stroma of the corpus luteum. Proges-terone secreted by the corpus luteum is responsible for the transformation of an estrogen-printed endometrium in a se-cretory endometrium necessary for embryo implantation. The corpus luteum plays a fundamental role in the implanta-tion and maintenance of early pregnancy as was shown in the early seventies with the removal of the corpus luteum in monkeys. Pregnancy was lost when that removal was made before 7 weeks of pregnancy [5]. The corpus luteum function is regulated by pituitary LH secretion. The frequency of pul-satile-releasing LH declines progressively throughout the luteal phase and it correlates with the intermittent corpus luteum progesterone secretion in the mid and late luteal phase [6]. When pregnancy occurs trophoblastic tissue pro-duces hCG which stimulates the corpus luteum and main-tains the estradiol and progesterone production in the early weeks of gestation.

Inadequate luteal function diagnosis takes into account the interval from the LH surge to menstruation. An interval of 11-13 days is considered normal but 10 days or less is considered a short luteal phase [7]. Furthermore, progester-one levels peak 6 to 8 days after ovulation, but there is no standard characterization of progesterone secretion during the luteal phase in normal fertile women [8]. It is difficult to establish a minimum serum progesterone concentration to define “fertile” luteal function. The corpus luteum function varies from cycle to cycle and there is no impact on his-tological dating of the endometrium with low levels of pro-gesterone (3-10 ng/mL) [9]. Currently, there is not a practical standard to diagnose inadequate luteal function. Many have considered the endometrial biopsy to be the most important diagnostic test to evaluate the luteal phase. However, recent prospective, blinded, randomized clinical trials suggest that

2 Current Drug Targets, 2013, Vol. 14, No. 8 Muñoz et al.

an endometrial biopsy is an imprecise tool for differentiating fertile women from women with an inadequate luteal func-tion [10].

LUTEAL FUNCTION IN CONTROLLED OVARIAN STIMULATION FOR IVF

The luteal phase, after controlled ovarian stimulation for IVF with GnRH analogues, becomes shorter and insufficient resulting in lower pregnancy rates [2, 11].

In the early luteal phase the production of progesterone is supraphysiological as a result of the presence of multiple corpora lutea. However, during the middle and late luteal phases there are low levels of LH and they are responsible for decreased progesterone levels. The principal mechanisms involved in the early luteolysis after ovarian stimulation is this low LH level because LH support through the luteal phase is entirely responsible for the maintenance of the cor-pus luteum [12].

The cause of luteal phase defect in stimulated cycles with the use of GnRH analogues could be a prolonged suppres-sion of pitutitary LH secretion pituitary down-regulation [4]. GnRHa induce a prolonged and deep pituitary suppression with recovery only after 2 or 3 weeks. However, when GnRHant are used, the recovery of pituitary FSH and LH production after the cessation of antagonist administration only takes 24 hours, but early luteolysis is still present in IVF ant cycles [13].

The most likely cause to explain the luteal defects in IVF is the supraphysiological steroid levels (high estradiol levels in early luteal phase) induced by ovarian stimulation which directly suppress the LH release from the pituitary via nega-

tive feedback action at the level of the hypothalamic-pituitary axis [14, 15].

Other less accepted theories have also been suggested such as the removal of large quantities of granulosa cells during oocyte retrieval [16] or hCG administration for final oocyte maturation producing a suppression of LH via short-loop feedback mechanism [17].

LUTEAL PHASE SUPPORT (LPS)

The luteal phase can be supported by gonadotropins, as hCG or LH, for stimulating the corpus luteum or supple-menting the steroids secreted by itself, especially progester-one. The first approach has the advantage to induce other substances secreted by the corpus luteum as prostaglandins, vasoactive-mediators or estrogens. The second one ensures the support of the main steroid necessary to transform the endometrium and maintain the early pregnancy.

To give support during the luteal phase in IVF has shown to improve pregnancy rates. Randomized controlled trials reported since the late eighties until 1999 comparing proges-terone versus placebo or non-treatment as luteal phase sup-port showed a higher clinical pregnancy rate in the group receiving treatment with progesterone. In fact, an increase of one and half to almost three fold in pregnancy rates is achieved by supplementing the luteal phase with progester-one as it is shown in Table 1 [18-25]. Therefore, since the late nineties no more studies have been reported regarding no luteal support probably due to the clear evidence of its bene-ficial effect in GnRHa IVF cycles. Conversely, pregnancy outcomes have not been shown to improve with luteal phase support in natural or unstimulated cycles [26].

Table 1. Randomized Controlled Trials Comparing Progesterone vs. Placebo or Non- Treatment as Luteal Phase Support (LPS).

Trial Stimulation protocol LPS control group(n) LPS study group (n) Clinical Pregnancy

Rate OR (IC 95%)

Belaisch-Allart,

et al. 1987 [18] CC + hMG or FSH + hMG

Placebo at embryo transfer day

and 4 days after (145) dydrogesterone (10 mg/8 h oral) (141) 1.47 (0.79- 2.75)

Kupfermincet al.

1990 [19] hMG from day 3 of menses

Oral placebo/8 hours for 14 days

(54) dydrogesterone (10 mg/8h oral) (51) 1.11 (0.48- 2.58)

Wong, et al. 1990

[20] CC + hMG No luteal support(10)

P4 (50 mg/day IM from day 2 until 11)

(10) 3.28 (0.39- 27.75)

Colwell, et al.

1991 [21]

C.C (100 mg oral from day

5 until 9) + hMG No luteal support (22) P4 (200 mg/6h oral) (12)

Ongoing pregnancy

rate 15.56(1.43-

169.7)

Artini, et al. 1995

[22] GnRHa + FSH No luteal support(44)

P4 (50 mg/day IM) or P4 (100 mg/day

vaginal) cream (88) 1.65 (0.56- 4.85)

Hurd, et al. 1996

[23] CC (100 mg oral) No luteal support (26)

P4 (100 mg /12h vaginal from embryo

transfer) + E2 valerate (2mg/8h oral)

(30)

3.73 (0.69- 20.06)

Abate, et al.

1999a [24] GnRHa + FSH Placebo /3 days (52)

P4 (50 mg/day IM) or P4 gel (90 mg/day

vaginal)(104) 3.23 (1.42- 7.34)

Abate, et al.

1999b [25]

GnRHa (400mg/12h s.c) +

FSH Placebo /3 days (43) 17-OHPc(341 mg/3 days IM) (43) 2.06 (0.79- 5.41)

Luteal Phase Support in Assisted Reproduction Current Drug Targets, 2013, Vol. 14, No. 8 3

One of the main difficulties in the clinical practice is to establish the endometrial effect of progesterone in the same cycle where the embryos are being transferred. That effect does not exclusively depend on serum progesterone (or es-tradiol) levels, but rather on endometrial receptors and probably on endometrial gene expression [27].

PROGESTERONE

Progesterone is actually considered the safest, most prac-tical and efficient drug to support the luteal phase in IVF. There are two different groups of progesterone: the natural progesterone and its derivatives (progesterone, dydropro-gesterone and medrogestone) and synthetic progesterone and its derivatives. There are two main groups of synthetic pro-gestins: the 17 hydroxyprogesterone derivatives and 19 nort-estosterone derivatives.

One of the most controversial issues is the route to ad-minister the progesterone. Whereas the vaginal route has some advantages such as; avoidance of local pain, avoidance of first pass hepatic metabolism, rapid absorption and most importantly a local endometrial effect [28], the intramuscular route seems to achieve a higher progesterone serum level but with more side effects such as painful injections, rashes, [29] inflammatory reactions and abscesses [30].

Four meta-analyses comparing vaginal vs intramuscular (IM) routes have been published from 2002 until now. The largest and the most recent reports 13 studies including 1098 events (548 in IM progesterone group, 550 in vaginal or rec-tal progesterone group) in 2932 participants. This showed similar clinical pregnancy rates between both routes (Peto OR of 1.14 (95% CI 0.97 to 1.33) [31]. Furthermore, it con-firms the findings of a previous meta-analysis with 9 ran-domized controlled trials. This analysis showed a compara-ble effect between vaginal progesterone as an oil-in-capsule or as a bioadhesive gel and IM progesterone administration on the endpoints of clinical pregnancy (OR 0.91, 95% [CI 0.74, 1.13]) and ongoing pregnancy (OR 0.94, 95% [CI 0.71, 1.26]). A nominally significantly lower rate of miscarriage was observed with vaginal progesterone compared with IM progesterone (OR 0.54, 95% [CI 0.29, 1.02]) [32]. However, two meta-analyses found lower clinical pregnancy rates when progesterone was administered by vaginal route com-pared with IM [4, 33].

Pritts et al in a meta-analysis in 2002 found better results with intramuscular progesterone when compared with vagi-nal progesterone. In all of the trials analyzed in this meta-analysis, either vaginal gel (Crinone

® 8) or vaginal cream

preparations were used for supplementation. Clinical preg-nancy and delivery rates were significantly improved when IM progesterone was used, with combined RR of 1.33 (95% CI 1.02-1.75) and 2.06 CI 95% (1.48 - 2.48), respec-tively [4]. A recent Cochrane systematic review [31] showed better pregnancy outcome with the use of synthetic proges-terone when compared with micronized progesterone, but no evidence favoring a specific route or duration of administra-tion was found.

A recent meta-analysis regarding the use of vaginal pro-gesterone gel for luteal support in IVF cycles, including seven randomized controlled trials, showed no significant differences between gel compared with all other vaginal pro-

gesterone forms in terms of clinical pregnancy. Similar clini-cal pregnancy rates were achieved with a single daily dose of 90 mg of vaginal progesterone gel compared to the standard care treatment of 600 mg (200 mg x 3) of vaginal progester-one capsules [34]. More recently, 8% Crinone vaginal gel was compared to intramuscular progesterone as luteal sup-port for day 3 cryopreserved embryo transfers. Similar im-plantation rates, but lower clinical and live birth rates were found in patients using Crinone compared with those with IM progesterone support [35]. However, this study defined implantation rate as the number of fetal heart beats at ultra-sound 6 weeks after transfer divided by the number of em-bryos transferred. This means that early miscarriage before heart beats are detected or anembrionic pregnancies are ex-cluded in spite of having implanted.

Although there is not a well-designed study to establish the optimal dose of vaginal progesterone, the most frequent daily dose is 600 mg of vaginal progesterone (200 mg, three times a day). In the natural progesterone group, the mi-cronized progesterone doses range from 100 to 800 mg/day. IM progesterone is used in doses from 25 to 50 mg daily. Dydrogesterone is the most commonly synthetic progester-one used in oral administration in doses from 10 to 30 mg daily.

hCG

hCG has also been used to support the luteal phase. It has been compared to placebo or non-treatment and it increases the clinical pregnancy rate up to a OR 3.37(0.61,18.58) as it is shown in Table 2 [19, 22, 36-38].

When hCG is compared to vaginal progesterone no dif-ferences in clinical pregnancy rates have been reported in randomized controlled trials. Moreover, a higher risk of ovarian hyperstimulation syndrome (OHSS) associated to hCG support was found, although that was not the main aim of those studies as it is shown in Table 3. [19, 39-46].

A comparison between hCG with IM progesterone shows opposite results in clinical pregnancy rates. Randomized controlled trials comparing IM progesterone ( from 25 to 100 mg/d) with hCG (from 1000 IU to 2500 IU every 2 or 3 days) report divergent clinical pregnancy rates as it is shown in Table 4 [20, 22, 47-50].

The addition of hCG to IM progesterone did not show any significant advantages in a study with a low number of patients [20].

ADDITION OF ESTRADIOL TO PROGESTERONE

Although, the effectiveness of progesterone for luteal support is clear, the role of additional supplementation with estradiol is still debatable. An adequate estradiol level is needed in follicular phase for endometrial priming and epi-thelium, glands, stroma and blood vessels proliferation, but the role of estradiol in the luteal phase is not clear. Luteal estradiol depletion does not seem to adversely affect the morphological developmental capacity of the endometrium [51].

Estradiol levels during the luteal phase do not correlate with the outcome of IVF cycles. This has been shown in a study of 763 assisted reproductive cycles which were divided

4 Current Drug Targets, 2013, Vol. 14, No. 8 Muñoz et al.

Table 2. Randomized Controlled Trials Comparing hCG vs. Placebo or Non-Treatment as Luteal Phase Support (LPS).

Trial Stimulation protocol LPS control group(n) LPS study group (n) Clinical Pregnancy

Rate (IC 95%)

Torode , et al. 1987

[36] CC + hMG Placebo (60)

hCG (1500 IU every other day)

(71) 1.24 (0.54- 2.58)

Belaisch-Allart, et

al. 1990 [37]

GnRHa in long or short protocol

+ hMG

Placebo at ET day and 4 days

after (193)

hCG (1500 IU s.c the ET day +

ET+4 day) (194) 1.38 (0.82- 2.32)

Kupfermincet al.

1990 [19] hMG from day 3 of menses

Oral Placebo/8 hours from ET for

14 days (51)

hCG (2500 IU IM on days +3,

+6, +10 after ET)(51) 0.82 (0.34- 1.98)

Artini, et al. 1995

[22] GnRHa + FSH No luteal support (44) hCG (2000 IU /3 days (44) 1.56 (0.42- 5.79)

Becker, et al, 2000

[38]

GnRHa(0.1 mg s.c, from cycle

day 1 until trigger) + hMG No luteal support (25)

hCG (1500 IU IM on OPU day

and OPU+2,+4 and +6 )(13) 3.37 (0.61-18.58)

Table 3. Randomized Controlled Trials Comparing hCG vs Vaginal Progesterone as Luteal Phase Support (LPS).

Trial Stimulation protocol LPS control group(n) LPS study group (n)

Clinical Pregnancy

Rate and OHSS OR

(IC 95%)

Kupfermincet 1990

[19] hMG from day 3 of menses P4 (10 mg/8 h oral) (54)

hCG (2500 IU IM, on days +3,

+6, +10 after ET )(51) 1.36 (0.58, 3.22)

Macrolin 1993 [39] long or short GnRHa protocol

+ hMG P4 (400 mg/day vaginal) (152)

P4 (400 mg/day vaginal) and hCG

(1500 IU every other day 3 times

from ET)(150)

1.05 (0.64, 1.72) 0.13

(0.02, 0.94)

Martínez 2000 [40] GnRHa(0.2 ml s.c) + FSH or

hMG P4 (100 mg/8 h vaginal) (168)

hCG (2500 IU IM, on OPU+2,

OPU+4, OPU+6 days)(142)

1.27 (0.80, 2.03) 0.84

(0.38, 1.89)

Ugur 2001 [41] GnRHa P4 (400 mg/day vaginal) (137) hCG (1500 IU/3 days) (81) 0.98 (0.54, 1.79) 0.37

(0.13, 1.02)

Ugur 2001 [41] GnRHa P4 (400 mg/day vaginal) (137)

P4 (400 mg/day vaginal) and

single dose of hCG (3000 IU on

day +7 after ET) (142)

1.05 (0.63, 1.77) 0.28

(0.14, 0.59)

Vimpeli 2001 [42] GnRHa + hMG P4 (200 mg/8 h vaginal) (44) hCG (1500 IU IM, on OPU+3,

OPU+6, OPU+9 days)(45) 1.15 (0.47, 2.82)

Ludwing 2001 [43] Long GnRHa protocol + r-FSH

or hMG P4 (200 mg /8 h vaginal) (70)

hCG (5000 IU , on ET day + ET

+3 day), hCG (2500 IU on 6 day

after ET) (77)

0.94 (0.41, 2.14) 0.77

(0.33, 1.80)

Ludwing 2001 [43] Long GnRHa protocol + r-

FSH or hMG P4 (200 mg/8 h vaginal) (70)

P4 (200 mg/8 h vaginal) + hCG

(5000 IU at ET day) (62)

0.86 (0.37, 2.03) 1.45

(0.54, 3.92)

Tay 2005 [45] “Standard” long GnRHa

protocol

P4 (90 mg/day vaginal) gel or

P4 (200 mg/12 hours rectal) or

P4 (200-400-600 mg vaginal)

(126)

hCG (1500 IU twice after oocyte

retrieval) (35) 1.03(0.47, 2.25)

Caligara 2007 [46] Not reported P4 (200 mg/12 h vaginal) (45)

P4 (200 mg/12 h vaginal) + hCG

(1000 IU s.c, on day +4, +7, +10

after OPU day) (47)

1.33 (0.58, 3.03)

Not reported

Lam 2008 [47] Long GnRHa(600 ug i.n) pro-

tocol + hMG or r-FSH

P4 (200 mg/8h vaginal) for 9

days + hCG (2000 IU on the

OPU day ,3, 6, 9 days after)

(89)

hCG (2000 IU IM, on the

OPUday + OPU+3, OPU+6,

OPU+9 days) (89)

1.39 (0.76, 2.52)

Luteal Phase Support in Assisted Reproduction Current Drug Targets, 2013, Vol. 14, No. 8 5

Table 4. Randomized Controlled Trials Comparing hCG vs Intramuscular (IM) Progesterone as Luteal Phase Support (LPS).

Trial Stimulation protocol LPS control group(n) LPS study group (n) Clinical Pregnancy

Rate (IC 95%)

Golan

1993 [48] GnRHa + hMG P4 (100 mg/24 h IM) (26)

hCG (1000 IU or 2000IU IM,

every 3 days 4 times )(30) 0.21 (0.05, 0.93)

Albert

1991 [49] GnRHa + hMG

P4 (50 mg IM, once the ET day

then P4 (12.5 mg/24 h IM) (23) hCG(2500 IU, 4 times) (34) 1.29 (0.34, 4.89)

Artini

1995 [22] GnRHa + FSH

P4 (50 mg/day IM) or P4 (100

mg/day vaginal) cream (88) hCG(2000IU/3 days ) (44) 1.10 (0.39, 3.06)

Fujimoto

2002 [50]

Long GnRHa (300 ug 3

times daily intrana-

sal)protocol + hMG

P4 (25 mg/day IM) (51) P4 (25 mg/day IM) + hCG (3000

IU IM, the days +1, +4, +7) (63) 0.37 (0.16, 0.88)

Wong

1990 [20] CC + hMG P4 (50 mg/day IM) (10)

P4 (50 mg/day IM) + hCG (1500

IU , alternate days from 5 to 15)

(10)

1.66 (0.23, 11.94)

Araujo

1994 [51] GnRHa + hMG

P4 (50 mg/day IM, from OPU +2

to OPU +14 days) (39)

hCG (2000 IU, on OPU+3,+6,+9

and+12 days) (38) 0.98 (0.68, 1.42)

up according to the ratio of the level of estradiol at hCG day to mid-luteal estradiol without differences in reproductive outcome among groups. It was concluded that a rapid decline in estradiol during mid-luteal phase does not associate with adverse IVF outcomes [52]. However, some authors have found a beneficial effect to add estradiol to progesterone to support the luteal phase in IVF agonists cycles [53-55]. A randomized controlled trial of 274 women undergoing their first IVF cycle were allocated to one of three luteal support groups. Group 1: only 100 mg/d of IM progesterone, Group 2: 100 mg/d of IM progesterone plus 6 mg/d of oral estra-diol, Group 3: 100 mg/d of IM progesterone plus 2500 IU of hCG administered in three doses. Higher pregnancy and im-plantation rates were found when estradiol was added to pro-gesterone compared to the use of progesterone alone [56]. These findings have not been confirmed by others [57, 58]. In GnRHant protocols, the addition of estradiol to progester-one does not seem to increase the probability of pregnancy either [59, 60].

The drugs most frequently used are estradiol valerate by oral or vaginal administration (from 2 mg to 6 mg daily) and transdermal estradiol (from 50 to 100 g twice a week).

A meta-analysis on luteal phase support [4] found an im-provement in implantation rates with the addition of oral estradiol in GnRHa protocols. Gelbaya et al, in a review in-cluding GnRHa and GnRHant cycles, concluded that the addition of estradiol for luteal phase support has no benefi-cial effect on pregnancy rates [61]. The most recent Coch-rane review also concluded that there is no benefit in clinical pregnancy, live birth delivery or spontaneous miscarriage rates [31].

GnRH AGONISTS

The beneficial effect of using GnRHa for a luteal phase support has been suggested in some studies. The majority of reported studies induce maturation oocyte with hCG injec-tions [62-65], except one that uses 100μg intranasal of

GnRHa for triggering ovulation [66]. In a recent meta-analysis it was concluded that the luteal-phase single-dose GnRHa administration can increase implantation rate in GnRHant protocol cycles. Nevertheless, by considering the heterogeneity among trials, it seems premature to suggest the use of GnRHa in the luteal phase as luteal support [67, 68]. Studies with GnRHa as luteal support are presented in Table 5. These studies suggested that the LH-releasing property of the GnRHa could have practical advantages over current treatment to obtain an adequate luteal support. Although the main advantage of this protocol should be to decrease the risk of OHSS, unfortunately, no study evaluated the OHSS incidence.

LUTEAL PHASE SUPPORT AFTER GnRHa TRIG-GERING OVULATION

The mid-cycle spontaneous LH surge has been replaced by hCG for triggering ovulation in assisted reproduction. However, the significantly longer half-life of hCG leads to undesirable clinical side effects such as OHSS. More re-cently, GnRHa are an alternative to hCG triggering in GnRHant protocols [69]. There are some differences be-tween spontaneous LH/FSH surge and GnRHa triggering. Whereas the spontaneous LH/FSH surge is characterized by three phases, the surge induced by GnRHa only has two phases [70]. The serum levels of estradiol and progesterone during the luteal phase are lower after GnRHa triggering compared to hCG triggering [71]. The shorter GnRHa in-duced LH elevation and the partial down-regulation of pitui-tary GnRH receptors result in reduced LH support and early luteolysis [70].

One of the major drawbacks of GnRHa triggering is the induction of an inadequate luteal phase, as was shown in a study with standard luteal phase support [72, 13]. Low clini-cal pregnancy rates (6%) and high pregnancy loss rates (79%) resulted when luteal support was sustained conven-tionally after GnRHa triggering [73]. Therefore, it is impor-tant to remember that after GnRHa triggering, the combined

6 Current Drug Targets, 2013, Vol. 14, No. 8 Muñoz et al.

Table 5. Randomized Controlled Trials in Normal Responders Comparing GnRHa to Other Luteal Phase Support.

Trial Stimulation

protocol

Triggering

ovulation GnRHa scheme (n) Control group (n)

Other medicines

(all patients) Results

Tesarik et al

2006 [63]

GnRHa long

protocol/GnRH-

ant multiple dose

+ r-FSH/hMG

r-hCG

Single injection (0.1mg

triptorelin) day 6 after

ICSI (150)

Placebo (150)

E2 valerate (4 mg)

+vaginal micronized

P4 (400 mg) +r-

hCG(single dose on

embryo transfer day)

Increased implan-

tation, clinical

pregnancy and

live birth rates

Pirard et al

2006 [67]

GnRHant multi-

ple dose + r-

FSH/hMG

r-hCG vs intrana-

sal GnRHa (0.2m

buserelin)

2 or 3/day intranasal

administration (100mg

buserelin) for a maxi-

mum of 15 days (5)

r-hCG +vaginal

micronized P4 (600

mg) (5)

None

Similar P4 serum

levels and

implantation rate

Ata et al

2008 [64]

GnRHa long

protocol + r-FSH hCG

Single injection (0.1

triptorelin) day 6 after

ICSI (285)

Placebo (285) vaginal progesterone

gel/90 mg No differences

Isik et al

2009 [65]

GnRHant multi-

ple dose +r-

FSH/hMG

hCG/r-hCG

Single injection (0.5 mg

leuprolide) day 6 after

ICSI (74)

None (80)

Vaginal micronized P4

(600 mg) +

hCG(single dose on

day 8 after ICSI)

Increased implan-

tation, clinical

pregnancy and

live birth rates

Razieh et al

2009 [66]

GnRHa long

protocol +r-FSH hCG

Single injection (0.1

triptorelin) day 5 or 6

after ICSI (74)

Placebo (80) Vaginal micronized

progesterone (800mg)

Increased

implantation and

clinical pregnancy

rates

effects of ovarian stimulation and GnRHa triggering reduce the endogenous LH concentrations dramatically [74] which implies a modification of the standard luteal phase supple-mentation [75].

In relation to the quality of the oocytes after triggering with GnRHa, the oocyte maturation seems appropriated as a folicullar pre-ovulatory maturation and an optimal matured oocyte liberation has been reported [76]. Furthermore, very acceptable clinical pregnancy rates were obtained in donor egg programs and frozen-thawed embryo transfers when the oocyte induction was made by GnRHa triggering [77, 78].

Many efforts have been made to overcome the luteal de-fects with no conventional protocols when GnRHa is used to trigger ovulation as intensive luteal phase support, hCG bo-lus or recombinant-LH.

INTENSIVE LUTEAL PHASE SUPPORT WITH

PROGESTERONE AND ESTRADIOL

An easier, adaptable luteal support is the increase in pro-gesterone and estradiol supplementation which has been suggested by Egmann et al. [79]. A randomized controlled trial comparing GnRHa vs hCG triggering was carried out in 66 patients. Authors evaluated whether there were any dif-ferences in the incidence of ovarian hyperstimulation syn-drome and implantation rates in high-risk patients undergo-ing IVF using a protocol consisting of GnRH agonist trigger after cotreatment with GnRH antagonist or hCG trigger after dual pituitary suppression protocol. They used a luteal phase support with intensive administration with 50 mg IM proges-terone and 0.1mg transdermal estradiol patches to maintain the serum estradiol levels over 200 pg/ml and progesterone

levels over 20 ng/ml after GnRHa triggering. With this pro-tocol the implantation rate was not affected. Additionally, no OHSS cases were seen in high-risk patients.

These findings were contrary to a previous study [80] in which a group of 28 OHSS high-risk patients were treated with luteal phase support with 50 mg/ day of IM progester-one, starting 36 h after oocyte retrieval. If serum E2 concen-tration was below 200 pmol/l, E2 was added (Estrofem, 4 mg/day ). If serum progesterone concentration was below 40 nmol/l, the progesterone dose was doubled. In this study a low ongoing pregnancy rate of 6% and a high rate of early pregnancy loss of 80% were found.

The benefit of intensive luteal support has been also con-firmed by others. A more recent and retrospective study [81] of 24 cycles of blastocyst transfer, showed the ongoing preg-nancy rate significantly increased with an enhanced luteal support protocol. A comparative study between IVF cycles, after triggering ovulation with GnRHa using intensive luteal phase support with the next first frozen-thawed embryo transfer cycles, showed similar implantation and live birth rates [78]. The predictive factors of successful outcome after GnRHa triggering and intensive luteal support have been recently reported. Serum LH and estradiol levels 4000 pg/mL on the day of the GnRHa trigger are important predic-tors of success in patients at high risk of OHSS [82]. The serum LH level on the day of the trigger is the most impor-tant predictor of clinical pregnancy after a GnRHa trigger. This level is significantly lower in patients with peak estra-diol < 4000 pg/mL, it is likely that the luteal phase serum LH level may also be lower, resulting in a more profound corpus luteum dysfunction [82].

Luteal Phase Support in Assisted Reproduction Current Drug Targets, 2013, Vol. 14, No. 8 7

hCG BOLUS

Some authors suggest the possibility of a good luteal phase support in both normoresponding as well as high risk OHSS patients, by using a low dose of 1500 IU hCG. This approach solves the decrease of LH activity in the luteal phase characteristic of cycles with GnRHa triggering.

Humaidan et al in a study with normoresponding patients established that the appropriated dose of hCG to an optimal luteal support was 1500 UI 35 hours post triggering. They suggest that this dose seems to secure a normal luteal phase and a normal clinical pregnancy [83].

A prospective, controlled study of three hundred and five patients who were randomized to ovulation induction with either 10,000 IU hCG or 0.5 mg GnRHa (buserelin) supple-mented with 1500 IU hCG on the day of oocyte retrieval. No significant difference was seen regarding positive pregnancy test results per embryo transfer (48% vs. 48%; OR 1.0 [95% CI 0.9–1.2]), clinical pregnancy rate per randomized patient (33% vs. 37%; OR 0.8 [95% CI 0.7–0.9]), ongoing preg-nancy rate per randomized patient (26% vs. 33%; OR 0.7 [95% CI 0.6–0.8]), and delivery rate per randomized patient (24% vs. 31%; OR 0.7 [95% CI 0.6–0.8]) between the GnRHa plus 1500 IU on the day of oocyte retrieval and hCG groups [84].

This protocol was applied to a group of high risk OHSS patients in “a proof- of- concept” study to test the safety. They showed a live birth rate of 50% and a reduced OHSS incidence (only one of twelve patients developed moderate late-onset OHSS) [74]. Other studies have been carried out to establish the optimal luteal support using hCG bolus. Shapiro BS et al., suggested that the beneficial effect of a dual triggering using 4 mg of GnRHa plus a low dose of hCG (1000-2500IU). They concluded that a concomitant lower dose of hCG with GnRHa triggering is associated with

higher ongoing pregnancy and implantation rates and lower pregnancy loss rates compared to the agonist triggering without this luteal support [85].

Serial low doses of hCG (1000 IU; 500 IU; 250 IU) dur-ing luteal phase in OHSS risk patients have been reported. They showed a pregnancy rate of 51.8% and a clinical preg-nancy rate of 43.4%. However, they registered 4.2% of mod-erate OHSS and 3.6% of cases of severe OHSS [86].

Recently, Kol S. et al defined a novel approach for luteal support. They suggested using a new luteal support using a total of two bolus of 1500 IU hCG in normoresponder pa-tients: one on the day of oocyte retrieval, and the other 4 days later. This luteal support without progesterone or estra-diol supplementation results in a 47% clinical ongoing preg-nancy rate and a 36% of early pregnancy loss. This group reported no OHSS incidences [87]. Studies using hCG as luteal support after GnRHa triggering are shown in Table 6.

LH

Stimulation of the corpus luteum depends on LH. How-ever, due to the short half-life of LH, it has traditionally been replaced by hCG. The main disadvantage of hCG is the asso-ciation with OHSS. The cause of inadequate function of the corpus luteum after GnRHa triggering is the low endogenous LH levels at early luteal phase. In order to simulate the natu-ral function, LH has been suggested as an alternative for luteal support. Supplementing this phase with recombinant LH has been considered an alternative to intensive luteal support or hCG bolus.

A comparison of LH concentration in the early and mid-luteal phase in IVF cycles after ovarian stimulation with hMG alone or in association with GnRHant showed similar low LH levels. These low LH serum concentrations may contribute to the luteal phase defect observed after ovarian

Table 6. Trials to Evaluate the Luteal Phase Support (LPS) After Triggering Ovulation with GnRHa.

Trial Type of

study

Risk

of

OHSS

Stimulation

protocol

Triggering

ovulation LPS study group (n)

Other medicines

(all patients) Results

Shapiro et

al 2008

[86]

Retrospec-

tive High

GnRHant

multiple

dose+r-

FSH/HMG

GnRH-a(4 mg

leuprolide

acetate s.c.+

hCG

E2 valerate and Progesterone

supplementation over 15ng/ml

and 200 pg/ml respectively (45)

CPR:53.3%, Live

birth rate: 53.3%,

OHSS incidence:

0%

Humaidan

et al 2009

[75]

Prospective

- proof of

concept

High

GnRH-ant

multiple

dose + r-FSH

GnRH-a (0.5

mg buserelin

s.c)

Single injection (1500 IU hCG

IM) 35 hours after OPU)(12)

Vaginal microni-

zed P4 (90 mg)

+E2 valerate (4

mg)

CPR: 50%, Live

birth rate:50%,

OHSS inci-

dence:0%.

Castillo et

al 2010

[87]

Retrospec-

tive-cohort-

based- non

controlled

No

GnRHant

multiple

dose + r-FSH

GnRH-a (0.1

mg leuprolide

acetate s.c)

Fixed low IM dose of hCG (250,

500 or 1000 IU) every third day

since day of OPU (192)

Vaginal mi-

cronized P4 (600

mg)

CPR:43.4%; OHSS

incidente: 7.8%

Kol et al

2011[88]

Prospective

- proof of

concept

No

GnRHant

multiple

dose + r-

FSH/hMG

GnRH-a(0.2

mg triptorelin

s.c)

Two injections (1500 IU hCG

IM) on OPU and OPU+4 days.

(15)

None

CPR: 47%; Early

pregnancy loss:

36%, OHSS inci-

dence: 0%

8 Current Drug Targets, 2013, Vol. 14, No. 8 Muñoz et al.

stimulation. Authors consider that supraphysiological steroid serum concentrations may interfere with LH secretion via long-loop feedback [88]. Only one study has been published using intermittent luteal phase recombinant LH administra-tion [89]. This study recruited 39 IVF patients who were randomized to one of the two branches. Seventeen patients received 250 g hCG recombinant for triggering ovulation, and 600 mg micronized progesterone vaginally from the day after oocyte retrieval. Eighteen patients received 0.2 mg of triptorelin for triggering ovulation plus six doses every other day of 300 IU recombinant LH (Luveris, Merck-Serono) starting on the day of oocyte retrieval. Similar implantation rates were achieved with the novel recombinant LH luteal support compared with the standard protocol. No cases of OHSS were recorded with either protocol [89]. In an attempt to evaluate the use of LH combined with progesterone during the luteal phase, 75 patients received vaginal progesterone alone and 75 received a combination of vaginal progesterone and recombinant LH (4 ampoules of LH on days 5,8,11 and 14 after hCG day). Authors conclude that LH at these doses did not influence pregnancy rate results [90].

We designed a study where fifteen oocyte donors were stimulated with recombinant FSH and GnRHant. They were

randomized to two modalities of final triggering and divided

into three groups: 5 patients received 250 μg of recombinant hCG (Ovitrelle Merck-Serono, Madrid, Spain) (hCG group)

and 10 received GnRHa (0.2 mg of triptoreline acetate SC,

Ipsen. Madrid, Spain). On the oocyte pick up (OPU) day, 5 patients from the GnRHa group started 150 IU of recombi-

nant LH (r-LH) (Luveris, Merck-Serono, Madrid Spain)

daily for 5 days plus vaginal progesterone: 200 mg BID(GnRHa A group). 5 patients only received r-LH with

the same doses (GnRH-a B group). The hCG group only

received the same dose of progesterone.

The main outcomes were serum progesterone, estradiol

on days 3 and 5 and OHSS incidence on day 5 after OPU day. No significant differences were noted for general char-

acteristics among the groups. A similar number of total oo-

cytes and MII was also found. Estradiol level was lower in both GnRHa groups on day 5 after the OPU day, and proges-

terone level was also lower in both GnRHa groups on days 3

and 5 after OPU (p: < 0.05) compared to the hCG group. However in both GnRHa groups, a progesterone level higher

than10 ng/mL was detected. No differences were found in

the ovarian size and maximum liquid pocket in the pouch of Douglas taken on day 5 after the OPU day among the

groups. Therefore, we concluded that the administration of

150 IU of recombinant LH daily is able to reverse the drop of progesterone due to the luteolysis after GnRH agonist

triggering of ovulation and it seems to be a safe strategy to

prevent OHSS [3].

THE LENGTH OF LUTEAL SUPPORT

When to Start Luteal Support

Progesterone supplementation may be started on the day

after the ovulatory hCG dose [91], on the day after the oo-cyte retrieval [92] or on the day of embryo transfer [93, 94].

A prospective randomized trial in an oocyte donation pro-

gram showed no differences in the implantation, pregnancy

and ongoing pregnancy rates when the progesterone was

delayed until the day of fertilization [95].

In IVF cycles in which ovarian stimulation is accompa-nied by high steroid levels, the endometrium may suffer a premature maturation at OPU day as has been extensively shown [96]. That means, it is difficult to study the need to start progesterone early if the endometrium has already achieved a premature advanced maturation.

When to Stop Luteal Support

Theoretically, the luteal insufficiency only exists in pa-

tients with ovarian function between the disappearance of exogenous hCG (6 days after oocyte pick-up) and the rise of

endogenous hCG with pregnancy. Nevertheless, there is a

large variation in the duration of luteal supplementation ad-ministration from 10 days up to 12 weeks of gestation.

If the pregnancy test is positive, progesterone may be continued up to 30 days after embryo transfer [50], until fetal heart activity is shown [93] or until the 12

th week of gesta-

tion [91]. In a randomized trial, three different times of onset the luteal support was analysed in IVF patients. From 385 patients, 130 started the progesterone after hCG, 128 patients at the day of oocyte retrieval and 127 at the day of embryo transfer. No differences were found in the ongoing preg-nancy rates among groups [97].

In a recent study, 220 patients with intrauterine preg-nancy (shown by transvaginal ultrasound) after IVF/ICSI, were randomized to suspend micronized progesterone as luteal support at week 5 or at week 8. A similar outcome in the cycles was achieved in both groups without any differ-ences in the miscarriage rates [98]. Other randomized trials had also confirmed these findings [99, 100]. Therefore, there is no proven role by adding progesterone or hCG for luteal support once a pregnancy has been established.

CONCLUSIONS

Abnormal luteal function is common in assisted repro-duction associated with ovarian stimulation but no diagnostic test for luteal phase insufficiency has been proven reliable in a clinical setting. The luteal phase after ovarian stimulation becomes shorter and insufficient, resulting in lower preg-nancy rates probably due to low levels of LH in the middle and late luteal phase.

Luteal support with progesterone or hCG improves preg-nancy outcomes and no differences are found among differ-ent routes of administration. However, hCG increases the risk of OHSS. The addition of estradiol or GnRHa as luteal support is not proven to be beneficial.

After GnRHa triggering, intensive luteal support or hCG bolus can overcome the defect in luteal phase, but more stud-ies are needed to show the LH utility as a support.

Finally, the day of starting the luteal support remains controversial and it does not seem necessary to continue it once a pregnancy has been established.

CONFLICT OF INTEREST

The author(s) confirm that this article content has no con-flicts of interest.

Luteal Phase Support in Assisted Reproduction Current Drug Targets, 2013, Vol. 14, No. 8 9

ACKNOWLEDGEMENT

The authors thank Ms. Rachel Allison for her exhaustive English grammar and orthographical review support.

LIST OF ABBREBIATIONS

BID = Bis in die

CC = Clomiphene Citrate

CPR = Clinical pregnancy rate

E2 = Estradiol.

ET = Embryo transfer

FSH = Follicle Stimulating Hormone

GnRHa = Gonadotrophin releasing hormone agonist

GnRHant = Gonadotrophin releasing hormone antagonist

hCG = Human chorionic gonadotropin

hMG = Human menopausal gonadotropin

ICSI = INTRACYTOPLASMIC sperm injection

IM = Intramuscular

i.n. = Intranasal

IVF = In Vitro fertilization

LH = Luteinizing hormone

LPS = Luteal phase support

MII = Metaphase II

OHSS = Ovarian hyperstimulation syndrome

OPU = Oocyte pick up

P4 = Progesterone

s.c. = Subcutaneous

REFERENCES

[1] Devoto L, Fuentes A, Kohen P, et al. The human corpus luteum:

life cycle and function in natural cycles. Fertil Steril 2009; 92: 1067-79.

[2] Smitz J, Devroey P, Camus M, et al. The luteal phase and early pregnancy after combined GnRH-agonist/HMG treatment for su-

perovulation in IVF or GIFT. Hum Reprod 1988; 3: 585-90. [3] Munoz E, Taboas E, Martinez B, Fernandez I, Aguilar J, Remohí J.

Recombinant LH rescues the luteal phase after GnRH agonist trig-gering of ovulation. A comparative study. Fertil Steril 2012; 98 (3):

S190. [4] Pritts EA, Atwood AK. Luteal phase support in infertility treat-

ment: a meta-analysis of the randomized trials. Hum Reprod 2002; 17: 2287-99.

[5] Csapo AI, Pulkkinen MO, Ruttner B, Sauvage JP, Wiest WG. The significance of the human corpus luteum in pregnancy mainte-

nance. I. Preliminary studies. Am J Obstet Gynecol 1972; 112: 1061-7.

[6] Filicori M, Butler JP, Crowley WF,Jr. Neuroendocrine regulation of the corpus luteum in the human. Evidence for pulsatile proges-

terone secretion. J Clin Invest 1984; 73: 1638-47. [7] Strott CA, Cargille CM, Ross GT, Lipsett MB. The short luteal

phase. J Clin Endocrinol Metab 1970; 30: 246-51. [8] Jordan J, Craig K, Clifton DK, Soules MR. Luteal phase defect: the

sensitivity and specificity of diagnostic methods in common clini-cal use. Fertil Steril 1994; 62: 54-62.

[9] Usadi RS, Groll JM, Lessey BA, et al. Endometrial development and function in experimentally induced luteal phase deficiency. J

Clin Endocrinol Metab 2008; 93: 4058-64.

[10] Murray MJ, Meyer WR, Zaino RJ, et al. A critical analysis of the

accuracy, reproducibility, and clinical utility of histologic endo-metrial dating in fertile women. Fertil Steril 2004; 81: 1333-43.

[11] Edwards RG, Steptoe PC, Purdy JM. Establishing full-term human pregnancies using cleaving embryos grown in vitro. Br J Obstet

Gynaecol 1980; 87: 737-56. [12] Duffy DM, Stewart DR, Stouffer RL. Titrating luteinizing hormone

replacement to sustain the structure and function of the corpus lu-teum after gonadotropin-releasing hormone antagonist treatment in

rhesus monkeys. J Clin Endocrinol Metab 1999; 84: 342-9. [13] Beckers NG, Macklon NS, Eijkemans MJ, et al. Nonsupplemented

luteal phase characteristics after the administration of recombinant human chorionic gonadotropin, recombinant luteinizing hormone,

or gonadotropin-releasing hormone (GnRH) agonist to induce final oocyte maturation in in vitro fertilization patients after ovarian

stimulation with recombinant follicle-stimulating hormone and GnRH antagonist cotreatment. J Clin Endocrinol Metab 2003; 88:

4186-92. [14] Fatemi HM. The luteal phase after 3 decades of IVF: what do we

know? Reprod Biomed Online 2009; 19 Suppl 4: 4331. [15] Fauser BC, Devroey P. Reproductive biology and IVF: ovarian

stimulation and luteal phase consequences. Trends Endocrinol Me-tab 2003; 14: 236-42.

[16] Kerin JF, Broom TJ, Ralph MM, Edmonds DK, Warnes GM, Jef-frey R, et al. Human luteal phase function following oocyte aspira-

tion from the immediately preovular graafian follicle of spontane-ous ovular cycles. Br J Obstet Gynaecol 1981; 88: 1021-8.

[17] Miyake A, Aono T, Kinugasa T, Tanizawa O, Kurachi K. Suppres-sion of serum levels of luteinizing hormone by short- and long-loop

negative feedback in ovariectomized women. J Endocrinol 1979; 80: 353-6.

[18] Belaisch-Allart J, Testart J, Fries N, Forman R G, Frydman R. The effect of dydrogesterone supplementation in an IVF programme.

Hum Reprod 1987; 2: 183-5. [19] Kupfermincet MJ, Lessing JB, Amit A, Yovel I, David MP, Peyser

MR. A prospective randomized trial of human chorionic go-nadotrophin or dydrogesterone support following in-vitro fertiliza-

tion and embryo transfer. Hum Reprod 1990; 5(3): 271-3. [20] Wong YF, Loong EPL, Mao KR, et al. Salivary oestradiol and

progesterone after in vitro fertilization and embryo transfer using different luteal support regimens. Reprod Fertil Dev 1990; 2: 351-

8. [21] Colwell KA, Tummon IS. Elevation of serum progesterone with

oral micronized progesterone after in vitro fertilization. J Reprod Med 1991; 36: 170-2.

[22] Artini PG, Volpe A, Angioni S, Galassi MC, Battaglia C, Genaz-zani AR. A comparative, randomized study of three different pro-

gesterone support of the luteal phase following IVF/ET program. J Endocrinol Invest 1995; 18: 51-6.

[23] Hurd W W, Randolph Jf J r, Christman G M, Ansbacher R, Menge A C, Gell J S. Luteal support with both estrogen and progesterone

after clomiphene citrate stimulation for in vitro fertilization. Fertil Steril 1996; 66: 587-92.

[24] Abate A, Brigandi A, Abate FG, Manti F, Unfer V, Perino M. Luteal phase support with 17alpha-hydroxyprogesterone versus un-

supported cycles in in vitro fertilization: a comparative randomized study. Gynecol Obstet Invest 1999; 48(2): 78-80.

[25] Abate A, Perino M, Abate FG, Brigandi A, Costabile L, Manti F. Intramuscular versus vaginal administration of progesterone for

luteal phase support after in vitro fertilization and embryo transfer. A comparative randomized study. Clin Exp Obstet Gynecol 1999;

26: 203-6. [26] Practice Committee of the American Society for Reproductive

Medicine. The clinical relevance of luteal phase deficiency: a committee opinion. Fertil Steril 2012; 98: 1112-7.

[27] Horcajadas JA, Pellicer A, Simon C. Wide genomic analysis of human endometrial receptivity: new times, new opportunities. Hum

Reprod Update 2007; 13: 77-86. [28] Posaci C, Smitz J, Camus M, Osmanagaoglu K, Devroey P. Pro-

gesterone for the luteal support of assisted reproductive technolo-gies: clinical options. Hum Reprod 2000; 15 Suppl 1: 129-48.

[29] Lightman A, Kol S, Itskovitz-Eldor J. A prospective randomized study comparing intramuscular with intravaginal natural progester-

one in programmed thaw cycles. Hum Reprod 1999; 14: 2596-9. [30] Propst AM, Hill JA, Ginsburg ES, Hurwitz S, Politch J, Yanush-

polsky EH. A randomized study comparing Crinone 8% and intra-

10 Current Drug Targets, 2013, Vol. 14, No. 8 Muñoz et al.

muscular progesterone supplementation in in vitro fertilization-

embryo transfer cycles. Fertil Steril 2001; 76: 1144-9. [31] van der Linden M, Buckingham K, Farquhar C, Kremer JA, Met-

wally M. Luteal phase support for assisted reproduction cycles. Cochrane Database Syst Rev 2011; (10): CD009154.

doi:CD009154. [32] Zarutskie PW, Phillips JA. A meta-analysis of the route of admini-

stration of luteal phase support in assisted reproductive technology: vaginal versus intramuscular progesterone. Fertil Steril 2009; 92:

163-9. [33] Daya S, Gunby J. Luteal phase support in assisted reproduction

cycles. Cochrane Database Syst Rev 2004; (3): CD004830. [34] Polyzos NP, Messini CI, Papanikolaou EG, et al. Vaginal proges-

terone gel for luteal phase support in IVF/ICSI cycles: a meta-analysis. Fertil Steril 2010; 94: 2083-7.

[35] Kaser DJ, Ginsburg ES, Missmer SA, Correia KF, Racowsky C. Intramuscular progesterone versus 8% Crinone vaginal gel for

luteal phase support for day 3 cryopreserved embryo transfer. Fertil Steril 2012; 98: 1464-9.

[36] Torode HW, Porter RN, Vaughan JI, Saunders DM. Luteal phase support after in vitro fertilisation: a trial and rationale for selective

use. Clin Reprod Fertil 1987; 5: 255-61. [37] Belaisch-Allart J, De Mouzon J, Lapousterle C, Mayer M. The

effect of HCG supplementation after combined GnRH ago-nist/HMG treatment in an IVF programme. Hum Reprod 1990; 5:

163-6. [38] Beckers NGM, Laven JSE, Eijkemans MJC, Fauser BCJM. Fol-

licular and luteal phase characteristics following early cessation of gonadotrophin-releasing hormone agonist during ovarian stimula-

tion for in-vitro fertilization. Hum Reprod 2000; 15(1): 43-9. [39] Macrolin G, Buvat J, Guittard C, Herbaut JC, Louvet AL, Dehaene

JL. Fécondation in vitro après agoniste de la LHRH: comparison randomisée de soutiens lutéaux par progestérone vaginale seule ou

associee a la gonadotrophine chorionique. Contraception Fertilité Sexualité 1993; 21(5): 434.

[40] Martinez F, Coroleu B, Parera N, et al. Human chorionic go-nadotropin and intravaginal natural progesterone are equally effec-

tive for luteal phase support in IVF. Gynaecological Endocrinology 2000; 14: 316-20.

[41] Ugur M, Yenicesu O, Ozcan S, Keles G, Gokmen O. A prospective randomized study comparing hCG, vaginal micronized progester-

one and a combination regimen for luteal phase support in an in-vitro fertilization programme. Fertil Steril 2001; 76 Suppl 1: 118.

[42] Vimpeli T, Tinkanen H, Huhtala H, Ronnberg L, Kujansuu E. Salivary and serum progesterone concentrations during two luteal

support regimens used in in vitro fertilization treatment. Fertil Steril 2001; 76: 847-8.

[43] Ludwig M, Finas A, Katalinic A, et al. Prospective, randomized study to evaluate the success rates using hCG, vaginal progesterone

or a combination of both for luteal phase support. Acta Obstetricia et Gynecologica Scandinavica 2001; 80: 574-82.

[44] Tay PYS, Lenton EA. The impact of luteal supplement on preg-nancy outcome following stimulated IVF cycles. Medical Journal

of Malaysia 2005; 60(2): 151-7. [45] Caligara C, Carranza F, Ramos J, Rodriguez I, Gonzalez A, Fer-

nandez-Sanchez M. Luteal phase support in IVF patients at low risk for OHSS: Progesterone vs. progesterone plus HCG. A pro-

spective randomized study. Fertil Steril 2007; 88: S163. [46] Lam PM, Cheung MC, Cheung LP, Lok HI, Haines CJ. Effects of

early luteal-phase vaginal progesterone supplementation on the outcome of in vitro fertilization and embryo transfer. Gynecologi-

cal Endocrinology 2008; 24 (12): 674-80. [47] Golan A, Herman A, Soffer Y, Bukovsky I, Caspi E, Ron-El R.

Human chorionic gonadotrophin is a better luteal support than pro-gesterone in ultrashort gonadotrophin-releasing hormone ago-

nist/menotrophin in-vitro fertilization cycles. Hum Reprod 1993; 8: 1372-5.

[48] Albert J, Pfeifer S. Luteal phase hormone levels after in vitro fer-tilization and embryo transfer (IVF-ET): a prospective randomized

trial of human chorionic gonadotropin (hCG) vs. intramuscular (im) progesterone (P) for luteal phase support following stimulation

with gonadotropin-releasing hormone agonist (GnRH-a) and hu-man menopausal gonadotropins (hMG). Fertil Steril 1991; S18.

[49] Fujimoto A, Osuga Y, Fujiwara T, et al. Human chorionic go-nadotropin combined with progesterone for luteal support improves

pregnancy rate in patients with low late-midluteal estradiol levels

in IVF cycles. Journal of Assisted Reproduction and Genetics

2002; 19(12): 550-4. [50] Araujo E Jr, Bernardini N, Frederick JL, Asch LH, Balmaceda JP.

Prospective randomized comparison of human chorionic go-nadotropin versus intramuscular progesterone for luteal-phase sup-

port in assisted reproduction. J Assist Reprod Genet 1994; 11 (2): 74-8.

[51] Younis JS, Ezra Y, Sherman Y, Simon A, Schenker JG, Laufer N. The effect of estradiol depletion during the luteal phase on endo-

metrial development. Fertil Steril 1994; 62: 103-7. [52] Hung Yu Ng E, Shu Biu Yeung W, Yee Lan Lau E, Wai Ki So W,

Chung Ho P. A rapid decline in serum oestradiol concentrations around the mid-luteal phase had no adverse effect on outcome in

763 assisted reproduction cycles. Hum Reprod 2000; 15: 1903-8. [53] Farhi J, Weissman A, Steinfeld Z, Shorer M, Nahum H, Levran D.

Estradiol supplementation during the luteal phase may improve the pregnancy rate in patients undergoing in vitro fertilization-embryo

transfer cycles. Fertil Steril 2000; 73: 761-6. [54] Lukaszuk K, Liss J, Lukaszuk M, Maj B. Optimization of estradiol

supplementation during the luteal phase improves the pregnancy rate in women undergoing in vitro fertilization-embryo transfer cy-

cles. Fertil Steril 2005; 83: 1372-6. [55] Drakakis P, Loutradis D, Vomvolaki E, et al. Luteal estrogen sup-

plementation in stimulated cycles may improve the pregnancy rate in patients undergoing in vitro fertilization/intracytoplasmic sperm

injection-embryo transfer. Gynecol Endocrinol 2007; 23: 645-52. [56] Ghanem ME, Sadek EE, Elboghdady LA, et al. The effect of luteal

phase support protocol on cycle outcome and luteal phase hormone profile in long agonist protocol intracytoplasmic sperm injection

cycles: a randomized clinical trial. Fertil Steril 2009; 92: 486-93. [57] Smitz J, Bourgain C, Van Waesberghe L, Camus M, Devroey P,

Van Steirteghem AC. A prospective randomized study on oestra-diol valerate supplementation in addition to intravaginal mi-

cronized progesterone in buserelin and HMG induced superovula-tion. Hum Reprod 1993; 8: 40-5.

[58] Lewin A, Benshushan A, Mezker E, Yanai N, Schenker JG, Goshen R. The role of estrogen support during the luteal phase of

in vitro fertilization-embryo transplant cycles: a comparative study between progesterone alone and estrogen and progesterone support.

Fertil Steril 1994; 62: 121-5. [59] Fatemi HM, Kolibianakis EM, Camus M, et al. Addition of estra-

diol to progesterone for luteal supplementation in patients stimu-lated with GnRH antagonist/rFSH for IVF: a randomized controlled

trial. Hum Reprod 2006; 21: 2628-32. [60] Ceyhan ST, Basaran M, Kemal Duru N, Yilmaz A, Goktolga U,

Baser I. Use of luteal estrogen supplementation in normal re-sponder patients treated with fixed multidose GnRH antagonist: a

prospective randomized controlled study. Fertil Steril 2008; 89: 1827-30.

[61] Gelbaya TA, Kyrgiou M, Tsoumpou I, Nardo LG. The use of es-tradiol for luteal phase support in in vitro fertiliza-

tion/intracytoplasmic sperm injection cycles: a systematic review and meta-analysis. Fertil Steril 2008; 90: 2116-25.

[62] Tesarik J, Hazout A, Mendoza-Tesarik R, Mendoza N, Mendoza C. Beneficial effect of luteal-phase GnRH agonist administration on

embryo implantation after ICSI in both GnRH agonist- and antago-nist-treated ovarian stimulation cycles. Hum Reprod 2006; 21:

2572-9. [63] Ata B, Yakin K, Balaban B, Urman B. GnRH agonist protocol

administration in the luteal phase in ICSI-ET cycles stimulated with the long GnRH agonist protocol: a randomized, controlled

double blind study. Hum Reprod 2008; 23: 668-73. [64] Isik AZ, Caglar GS, Sozen E, Akarsu C, Tuncay G, Ozbicer T, et

al. Single-dose GnRH agonist administration in the luteal phase of GnRH antagonist cycles: a prospective randomized study. Reprod

Biomed Online 2009; 19: 472-7. [65] Razieh DF, Maryam AR, Nasim T. Beneficial effect of luteal-phase

gonadotropin-releasing hormone agonist administration on implan-tation rate after intracytoplasmic sperm injection. Taiwan J Obstet

Gynecol 2009; 48: 245-8. [66] Pirard C, Donnez J, Loumaye E. GnRH agonist as luteal phase

support in assisted reproduction technique cycles: results of a pilot study. Hum Reprod 2006; 21: 1894-900.

[67] Oliveira JB, Baruffi R, Petersen CG, Mauri AL, Cavagna M, Fran-co JG,Jr. Administration of single-dose GnRH agonist in the luteal

Luteal Phase Support in Assisted Reproduction Current Drug Targets, 2013, Vol. 14, No. 8 11

phase in ICSI cycles: a meta-analysis. Reprod Biol Endocrinol

2010; 8: 107,7827-8-107. [68] Ata B, Urman B. Single dose GnRH agonist administration in the

luteal phase of assisted reproduction cycles: is the effect dependent on the type of GnRH analogue used for pituitary suppression? Re-

prod Biomed Online 2010; 20: 165,6; author reply 167. [69] Lanzone A, Fulghesu AM, Apa R, Caruso A, Mancuso S. LH surge

induction by GnRH agonist at the time of ovulation. Gynecol En-docrinol 1989; 3: 213-20.

[70] Kol S. Luteolysis induced by a gonadotropin-releasing hormone agonist is the key to prevention of ovarian hyperstimulation syn-

drome. Fertil Steril 2004; 81: 1-5. [71] Itskovitz J, Boldes R, Levron J, Erlik Y, Kahana L, Brandes JM.

Induction of preovulatory luteinizing hormone surge and preven-tion of ovarian hyperstimulation syndrome by gonadotropin-

releasing hormone agonist. Fertil Steril 1991; 56: 213-20. [72] Fauser BC, de Jong D, Olivennes F, et al. Endocrine profiles after

triggering of final oocyte maturation with GnRH agonist after cotreatment with the GnRH antagonist ganirelix during ovarian hy-

perstimulation for in vitri fertilization. J Clin Endocrinol Metab 2002; 87: 709-15.

[73] Humaidan P, Bredkjaer HE, Bungum L, et al. GnRH agonist (buserelin) or hCG for ovulation induction in GnRH antagonist

IVF/ICSI cycles: a prospective randomized study. Hum Reprod 2005; 20: 1213-20.

[74] Humaidan P. Luteal phase rescue in high-risk OHSS patients by GnRHa triggering in combination with low-dose HCG: a pilot

study. Reprod Biomed Online 2009; 18: 630-4. [75] Humaidan P, Papanikolaou EG, Kyrou D, et al. The luteal phase

after GnRH-agonist triggering of ovulation: present and future per-spectives. Reprod Biomed Online 2012; 24: 134-41.

[76] Andersen CY, Humaidan P, Ejdrup HB, Bungum L, Grondahl ML, Westergaard LG. Hormonal characteristics of follicular fluid from

women receiving either GnRH agonist or hCG for ovulation induc-tion. Hum Reprod 2006; 21: 2126-30.

[77] Griesinger G, Kolibianakis EM, Papanikolaou EG, et al. Triggering of final oocyte maturation with gonadotropin-releasing hormone

agonist or human chorionic gonadotropin. Live birth after frozen-thawed embryo replacement cycles. Fertil Steril 2007; 88: 616-21.

[78] Imbar T, Kol S, Lossos F, Bdolah Y, Hurwitz A, Haimov-Kochman R. Reproductive outcome of fresh or frozen-thawed em-

bryo transfer is similar in high-risk patients for ovarian hyperstimu-lation syndrome using GnRH agonist for final oocyte maturation

and intensive luteal support. Hum Reprod 2012; 27: 753-9. [79] Engmann L, DiLuigi A, Schmidt D, Nulsen J, Maier D, Benadiva

C. The use of gonadotropin-releasing hormone (GnRH) agonist to induce oocyte maturation after cotreatment with GnRH antagonist

in high-risk patients undergoing in vitri fertilization prevents the risk of ovarian hyperstimulation syndrome: a prospective random-

ized controlled study. Fertil Steril 2008; 89: 84-91. [80] Babayof R, Margalioth EJ, Huleihel M, et al. Serum inhibin A,

VEGF and TNFalpha levels after triggering oocyte maturation with GnRH agonist compared with HCG in women with polycystic ova-

ries undergoing IVF treatment: a prospective randomized trial. Hum Reprod 2006; 21: 1260-5.

[81] Shapiro BS, Daneshmand ST, Garner FC, Aguirre M, Hudson C. Comparison of "triggers" using leuprolide acetate alone or in com-

bination with low-dose human chorionic gonadotropin. Fertil Steril 2011; 95: 2715-7.

[82] Kummer N, Benadiva C, Feinn R, Mann J, Nulsen J, Engmann L. Factors that predict the probability of a successful clinical outcome

after induction of oocyte maturation with a gonadotropin-releasing hormone agonist. Fertil Steril 2011; 96: 63-8.

[83] Humaidan P, Bungum L, Bungum M, Yding Andersen C. Rescue of corpus luteum function with peri-ovulatory HCG supplementa-

tion in IVF/ICSI GnRH antagonist cycles in which ovulation was triggered with a GnRH agonist: a pilot study. Reprod Biomed On-

line 2006; 13: 173-8. [84] Humaidan P, Ejdrup Bredkjaer H, Westergaard LG, Yding Ander-

sen C. 1,500 IU human chorionic gonadotropin administered at oo-

cyte retrieval rescues the luteal phase when gonadotropin-releasing

hormone agonist is used for ovulation induction: a prospective, randomized, controlled study. Fertil Steril 2010; 93: 847-54.

[85] Shapiro BS, Daneshmand ST, Garner FC, Aguirre M, Thomas S. Gonadotropin-releasing hormone agonist combined with a reduced

dose of human chorionic gonadotropin for final oocyte maturation in fresh autologous cycles of in vitri fertilization. Fertil Steril 2008;

90: 231-3. [86] Castillo JC, Dolz M, Bienvenido E, Abad L, Casan EM, Bonilla-

Musoles F. Cycles triggered with GnRH agonist: exploring low-dose HCG for luteal support. Reprod Biomed Online 2010; 20:

175-81. [87] Kol S, Humaidan P, Itskovitz-Eldor J. GnRH agonist ovulation

trigger and hCG-based, progesterone-free luteal support: a proof of concept study. Hum Reprod 2011; 26: 2874-7.

[88] Tavaniotou A, Albano C, Smitz J, Devroey P. Comparison of LH concentrations in the early and mid-luteal phase in IVF cycles after

treatment with HMG alone or in association with the GnRH an-tagonist Cetrorelix. Hum Reprod 2001; 16: 663-7.

[89] Papanikolaou EG, Verpoest W, Fatemi H, Tarlatzis B, Devroey P, Tournaye H. A novel method of luteal supplementation with re-

combinant luteinizing hormone when a gonadotropin-releasing hormone agonist is used instead of human chorionic gonadotropin

for ovulation triggering: a randomized prospective proof of concept study. Fertil Steril 2011; 95: 1174-7.

[90] Geber S, Maia L, Lauar I, Valle MP, Sampaio AC. Does recombi-nant LH combined to progesterone for luteal phase interfere in the

outcome of assisted reproduction technique cycles? [abstract]. Fer-til Steril 2007; 88 Suppl 1:25.

[91] Smitz J, Devroey P, Faguer B, Bourgain C, Camus M, Van Steirteghem AC. A prospective randomized comparison of intra-

muscular or intravaginal natural progesterone as a luteal phase and early pregnancy supplement. Hum Reprod 1992; 7: 168-75.

[92] Buvat J, Marcolin G, Guittard C, Herbaut JC, Louvet AL, Dehaene JL. Luteal support after luteinizing hormone-releasing hormone

agonist for in vitri fertilization: superiority of human chorionic go-nadotropin over oral progesterone. Fertil Steril 1990; 53: 490-4.

[93] Claman P, Domingo M, Leader A. Luteal phase support in in-vitro fertilization using gonadotrophin releasing hormone analogue be-

fore ovarian stimulation: a prospective randomized study of human chorionic gonadotrophin versus intramuscular progesterone. Hum

Reprod 1992; 7: 487-9. [94] Pouly JL, Bassil S, Frydman Rea. Support de la phase lutéale par la

progestérone vaginale: etude comparative avec la progestérone mi-cronisée per os. Contracept-Fertil-Sex 1997; 25: 596-601.

[95] Escriba MJ, Bellver J, Bosch E, Sanchez M, Pellicer A, Remohi J. Delaying the initiation of progesterone supplementation until the

day of fertilization does not compromise cycle outcome in patients receiving donated oocytes: a randomized study. Fertil Steril 2006;

86: 92-7. [96] Kolibianakis E, Bourgain C, Albano C, et al. Effect of ovarian

stimulation with recombinant follicle-stimulating hormone, go-nadotropin releasing hormone antagonists, and human chorionic

gonadotropin on endometrial maturation on the day of oocyte pick-up. Fertil Steril 2002; 78: 1025-9.

[97] Mochtar M, Van Welly M, Van der Veen F. Timing luteal phase support in GnRH agonist down-regulated IVF/embryo transfer cy-

cles. Hum Reprod 2006; 21: 905-8 [98] Kohls G, Ruiz F, Martinez M, et al. Early progesterone cessation

after in vitri fertilization/intracytoplasmic sperm injection: a ran-domized, controlled trial. Fertil Steril 2012; 98: 858-62.

[99] Kyrou D, Popovic-Todorovic B, Fatemi HM, et al. Does the estra-diol level on the day of human chorionic gonadotrophin administra-

tion have an impact on pregnancy rates in patients treated with rec-FSH/GnRH antagonist? Hum Reprod 2009; 24: 2902-9.

[100] Goudge CS, Nagel TC, Damario MA. Duration of progesterone-in-oil support after in vitro fertilization and embryo transfer: a ran-

domized, controlled trial. Fertil Steril 2010; 94: 946-51.

Received: January 07, 2013 Revised: February 26, 2013 Accepted: April 20, 2013