multiple pregnancy

MULTIPLE PREGNANCY

DR ENIE AKHTAR BT NAWAWI

Why?

Heredity Older women High parity Race Ovulation induction IVF

How?

usually occurs when more than one egg is fertilized and implants in the uterus.

Sometimes, one egg is fertilized and then divides into two or more embryos. Identical multiples may have individual placentas and amniotic sacs, but most share a placenta with separate sacs. Rarely, identical twins share one placenta and a single amniotic sac.

Types:

Monozygotic– 3-5/1000 LB

Dyzygotic– 4-50/1000 LB

Zygosity- refers to type of conception

Chorionicity-refers to type of placenta

Seventy percent of twins are dizygotic, resulting from the fertilization of two ova, whereas 30% are monozygotic, arising from a single fertilized ovum .

Three placentation types can occur depending on the timing of the development of twins from fertilization. From earlier division to later, the three types of placentation are dichorionic-diamniotic, monochorionic-diamniotic, and monochorionic-monoamniotic.

Dizygotic twins are always dichorionic. Monozygotic twins are dichorionic in one-third of cases,

monochorionic-diamniotic in two-thirds of cases, and monochorionic pregnancies are seen in less than 1% of cases

Antenatal assessment-<20/52->20/52

Assessment of chorionicity(can be assessed accurately in 100% of cases when performed <13/52)

Opportunity to screen for chromosomal abnormality by NT

Maternal complication– PE and APH(PP or AP), preterm labour,anaemia,PPH

Fetal complication– IUGR(12-47%),single IUD(2.5-5%),monoamniotic

pregnancy, TRAP sequence,conjoined twin,TTTS

Determination of chorionicity-important in stratification of clinical risk,genetic counselling

and prenatal screening and diagnosis of structural and chromosomal abN

criterion monochorionicity dichorionicity

Placenta Single(42%) Separate(98%)

Fetal sex Concordant(40%) Discordant(100%)

Dividing membrane Absent-MCMA(100%)

No of layers 2 layers(94%) 4 layers(100%)

Thickness <2mm(39-82%) >2mm(95%)

Twin peak sign Nil(44%) Present(100%)

Use of all criteria 92% 97%

Twin peak sign/ lambda sign

Management

*The risks for women with multifetal pregnancies include preterm labor, premature rupture of membranes, gestational hypertension or preeclampsia, gestational diabetes, anemia, and thromboembolism.

Management

 Delivery of more than one baby is also more complicated, with a greater risk of cesarean delivery and postpartum hemorrhage. 

Because of the high rate of preterm delivery in multiple gestations, these babies are at greater risk for adverse neurologic outcomes, such as cerebral palsy, compared with a singleton pregnancy. 

Additionally, fetuses in multiple gestations have a greater risk of chromosomal and structural abnormalities.

..single IUD

Influenced by chorionicity DC

– Seldom a risk factor for the healthy surviving co-twin

MC– Delivery soon may prevent sudden demise of the

co-twin but is unlikely to reduce the neurological morbidity of the survivor

..monoamniotic-suspect in single pl mass with same sex,normal amniotic volume,absence of dividing membrane on 2 exam and unrestricted FM

Cord entanglement MOD- el LSCS before term

TRAP(Twin reversed arterial perfusion)/acardiac-where fetal tissue part grow in tandem with the normal fetus and are perfused in the reversed direction with deO2 blood entering the single umbilical artery

Nly formed twin=pump twin Risk-cardiac failure or preterm delivery PNM 50% while the perfused fetus is never

viable Occur due to primary failure of cardiac

development early in embryogenesis from chromosomal abN

Dx- US-grossly malformed fetus with no FH

…TTTS-acute/chronic

Severe case- when deep A-V anastomoses are uncompensated by supreficial A-A and V-V anastomoses, with resultant net flow in one direction,causing associated hypovolemia in one twin and volume overload in the other.

Acute-dx-postnatal ie Hb difference Chronic-dx-discordant fetal size with severe poly

around larger twin and oligo ar the smaller stuck twin

Perinatal mortality and morbidity

6x higher-mainly due to immaturity Others-IUD, cerebral atrophy,cerebral palsy

INTRAPARTUM CARE

The increased incidence of fetal malpresentation,preterm labour,IUGR and placental abnormalities,together with the need for skilled obstetrical maneuvres,suggest thet appropriate intrapartum management is an important as intensive antenatal care to improve overall neonatal morbidity and mortality

Mode of delivery

Vaginal Caesarean

– Non-cephalic presentation of 1st twin– Placenta praevia– Antepartum death of 1st twin– Monoamniotic twin,IUGR,chronic TTTS

Combined (ie CS for the 2nd twin)

VD in twin pregnancy

Timing of delivery-38-40/52 Management of labour

– First stage IV line, partogram, continous CTG monitoring, ensure good contraction,

augmentation after discuss with specialist, adequate pain relief preferably epidural– Second stage

Inform Paeds Delivery of 2nd twin Palpate abdomen immediately-aim:longitudinal External version to either breech/cephalic according to the ease and the

proximity of the presenting part to the pelvic brim…breech extraction. If fail version-internal podalic version

Use of immediate augmentation using oxytocin Ensure no undiagnosed triplet before giving Syntometrine

….continue

– Third stage IM Syntometrine 1 ml after delivery of the second twin Deliver placenta by CCT IV oxytocin Examine the placenta for type of chorionicity and

completeness and document findings properly

Issues on twin delivery at second stage

The optimal delivery interval between twins in vaginal twin delivery

– It is reasonable to either: Expedite delivery by oxytocin infusion, stabilising amniotomy and if

indicated operative vaginal delivery Permit a longer delay between deliveries and continuous EFM. For

the non cephalic second twin, if breech extraction is considered, this should be done without delay

No clear time limit is required as long as continuous FHR monitoring of second twin can be achieved and reassuring in cephalic second twin. No hard and fast rule in regards to this but up to 30 minutes is acceptable.

Thank you