Cervical Ripening andInduction/Augmentation of Labor
Daren Sachet, RNC/MPA
ObjectivesList the indications and
contraindications for cervical ripening and induction of labor.
Discuss the different methods used for cervical ripening, labor induction and augmentation.
Discuss the nurses role in the safe administration of cervical ripening and induction agents.
DefinitionsWhat is cervical ripening?
Preparation of an unfavorable cervix for labor induction
What is induction?Stimulation of uterine contractions
before the spontaneous onset of labor
What is augmentation?Correcting ineffective uterine
contractions or hypocontractility
Incidence in the United States
Since 1989, there has been a 137% increase in induction and a 75% increase in augmentation
rates.NCHS, 2009
Risk-BenefitRisk of Cesarean Birth for Nulliparous
Women:17.2% spontaneous labor30.4% induced labor77.7% increase for induction
Reisner et al., 2009
Use of pharmacologic agents increases risk for tachysystole, indeterminate or abnormal FHR patterns and failure to progress
Cascade of Interventions Related to Induction of Labor
•IV•Bedrest•Continuous EFM•Amniotomy•Significant Pain•Epidural•Prolonged Labor
Economic CostsSpontaneous Labor/vaginal birth $4000Induction of labor/vaginal birth
$5000Cesarean Birth/scheduled
$7000Cesarean Birth/failed induction
$7500Simpson, KR., 2009
Simpson, 2009
Indeterminate/Abnormal FHR(Category II and Category III FHR)
Nearly twice the risk, possibly related to:TachysystoleEarly AmniotomyLabor DystociaLonger LaborLess Fetal Tolerance
Glantz, 2005, Simpson, KR., 2009
Risks to the Infant
Respiratory Distress SyndromeTTNHypoglycemiaSepsisAdmission to higher level of nursery care> LOS
Tita, 2009
Indications for Cervical Ripening and Induction of Labor
MedicalPremature rupture of membranes, post term pregnancy, preeclampsia, diabetes, fetal compromise. Induction without a medical indication is discouraged but according to ACOG, labor may be induced for logistic or “psychosocial indications”. It is not recommended to induce these patients until 39 completed weeks and should only be undertaken after fully informing the woman of potential risks involved.Joint Commission Perinatal Care Quality Measure Decrease the rate of women with elective delivery at 37-39 weeks.
Contraindications-Induction of Labor
Generally, the contraindications for labor induction are the same as those for spontaneous labor and vaginal birth
Vasa previa or complete placenta previaTransverse fetal lieUmbilical cord prolapsePrevious transfundal uterine incisionActive genital herpes infectionPelvic structural deformitiesInvasive cervical cancer
Situations Requiring Special Attention
One or more previous low-transverse cesarean births Breech presentation Maternal heart disease Multifetal pregnancy Polyhydramnios Presenting part above the pelvic inlet Severe hypertension Abnormal FHR patterns requiring emergent birth A trial of labor after a previous cesarean birth or history
of prior uterine scar
ACOG 2009, 2002
Indications for Augmentation of Labor
DystociaUterine Hypocontractility
Uterine hypocontractility should be augmented only after both the maternal pelvis and fetal presentation have been assessed.
ACOG 2009
Pre-induction/Ripening Criteria
Availability of trained nursing and provider staffCervical ripening agents should be administered
at or near the labor and birth suite where uterine activity and FHR can be monitored continually
Assessment of gestational age, cervical status, pelvic adequacy, fetal size and presentation
A physician capable of performing a cesarean birth should be readily available.
ACOG 2009
Criteria continued
Considerations to any risks to mother or fetusPatient counseling regarding indications,
agents/methods, and possibility of repeat induction or cesarean birth
The medical record should document that a discussion was held between the pregnant woman and her health care provider
ACOG 2009
Bishop ScoreHas been shown to be an important determinant of
the success or failure of inductionScore Dilate
cmEfface% Station Consis-
tencyPos Cx
0 Closed 0-30 -3 Firm Post
1 1-2 40-50 -2 Med mid
2 3-4 60-70 -1/0 Soft Ant
3 5-6 80 +1/+2 ___ ___
Cervical Status
For women at term, a Bishop score of 6 or more may be useful in predicting onset of spontaneous labor within 7 days
Rozenberg, Goffinet & Hessabi, 2000
Cervical Ripening Agents
These agents may soften the cervix and change the Bishop score
Mechanical/Non pharmacologic Methods
Pharmacologic Methods
Mechanical Dilators
Laminaria Tents Synthetic Osmotic DilatorsFoley CatheterDouble Balloon Cervical Ripening
Catheter Extraamniotic saline infusion- balloon
catheter
Pharmacologic MethodsNot recommended for use in women with
history prior c-birth or uterine scar
Prostaglandin E1: Misoprostol (Cytotec)Oral or vaginal use
Wide variations exist in time of onset of uterine contractions
Peak action is approximately 1-2 hours but can be up to 4-6 hours
May re-dose only if parameters met
Complications with Misoprostol (Cytotech)
TachysystoleIndeterminate/Abnormal FHR patternPrecipitous LaborsUterine RuptureNeed careful maternal/fetal assessmentsNeed consent/protocols
ACOG, 2009
Prostaglandin E2-Dinoprostone
Prepidil
Cervidil
Cervical Ripening Agents
Minimum safe interval from prostaglandin to oxytocin administration not established
Manufacturers guidelines recommendMisoprostol- at least 4 hours after last dosePrepidil- 6-12 hours after last doseCervidil-30-60 minutes after removal of
vaginal insertNot contraindicated with PROM
Induction and Augmentation of Labor
Mechanical methods of Induction of Labor
Stripping the MembranesAmniotomy
OxytocinMost commonly used induction agent in the
United States and worldwide Kelly & Tan, 2001
Synthetic oxytocin is chemically and physiologically identical to endogenous oxytocin
Half life between 10-12 minutes Dawood, 1995a; Arias, 2000
3 – 4 half-lives to reach steady stateFull effects of oxytocin cannot be determined
until steady-state concentration has been achieved.
Physiologic steady state 40 min, basis for dosing interval.
Endogenous Oxytocin
First Stage LaborMaternal circulating concentration 2-4
mU/minFetal Contribution3 mU/minCombined effects = 5-7 mU/min
Second Stage LaborSurge of oxytocin at Ferguson’s reflex
Simpson, KR, 2009
Response to Oxytocin
Prolonged exposure → Oxytocin receptor sites compared with spontaneous labor
More oxytocin for dysfunctional labor will cause further desensitization. A rest period of 1-2 hours is recommended
Phaneuf et al., 2000
Continued oxytocin after active labor is established will not shorten labor. Active labor is self-sustaining.
Oxytocin Dosing
Considerable controversy exists about dosage and rate increase intervals-there is no consensus in
the literature
You take the high road …
and I’ll take the low road
Oxytocin DosingOnly increase oxytocin rate if:FHR is normalLabor has not progressed 0.5 -1 cm/hrContractions are no closer than every 2-3
minutes
Excessive uterine activity over the course of 1 hour in first stage of labor is associated with an umbilical artery pH ≤ 7.11 at birth
Decrease or discontinue oxytocin in active labor
Simpson, KR, 2009
Physiologic Dosage
Start with doses of 0.5-1 mU/minIncrease in 1-2 mU/min increments every 30-
40minutes until contractions are every 2-3 minutes apart and labor is progressing ACOG, 2009 SOGC, 2001
Current literature suggests that 90% of pregnant women at term will have labor successfully induced with 6mU/min or less of oxytocin
Dawood, 1995a, 1995b; Seitchik, Amico et al., 1984
Oxytocin Administration
No maximal dose of oxytocin has been firmly established
Doses above 40mU/min are rarely used, except in cases of intrauterine fetal demise (IUFD).
Infusion rates >=20mU/min can decrease free water clearance by the kidney resulting in water intoxication.
Smith and Merrill, 2006
High Dose Oxytocin
According to ACOG (2009), protocols that involve “high-dose” oxytocin are acceptable; however, high-dose oxytocin is associated with more uterine tachysystole
Oxytocin and Medication Safety
August 2007 oxytocin added to the Institute for Safe Medication Practices to the High Alert Medication list.Joint Commission Standard MM.7.10
The organization develops processes for managing high-risk or high-alert medicationsThe organization must develop additional processes for selecting, procuring, storing, ordering, transcribing, preparing, dispensing, administering and monitoring these high-risk or high-alert medications.
Nursing responsibilities
Titrate oxytocin infusion drip to achieve three contractions in 10 minutes with a duration of 60-90 seconds
Closely monitor fetal response, uterine activity and resting tone
Monitor maternal vital signs and fluid balance
Potential Complications-Oxytocin
Tachysystole >5 contractions in 10 minutes, averaged over a 30-minute
window. Tachysystole should always be qualified as to the presence or absence of associated FHR decelerations.
Abruptio placentaeUterine ruptureHyponatremia (water intoxicaiton)
I & O when on oxytocin
Nursing Interventions for Tachysystole with Normal FHR
patternLateral positioning of motherIncrease IV fluid (LR)If uterine activity not returned to normal
after 10 minutes, oxytocin by halfIf tachysystole persists, D/C oxytocin until
tachysystole resolvesConsider terbutaline 0.25 mg SQ, with
order ACOG, 2010, AWHONN, 2008
Nursing Interventions for Tachysystole with Indeterminate
or Abnormal FHR patternDiscontinue or reduce oxytocinLateral positioning of MotherIV fluid bolus (LR)If hypotensive, (as with epidural) contact
anesthesia provider, prepare to administer epinephrine, with order
Oxygen, 10 LPM, non-rebreather maskConsider terbutaline 0.25 SQ, with orderIf unresolved, inform provider immediately,
possibly prepare for C/S. (ACOG 2010)
Resuming Oxytocin
Once uterine activity and FHR pattern are normal:If oxytocin was discontinued >20-30 minutes, resume at no > ½ the rate that caused tachysystole. Gradually increase rate if needed based on protocol and maternal/fetal statusIf oxytocin was discontinued >30-40 minutes resume at initial dose ordered
Women attempting VBAC
Should women with a previous cesarean birth undergo induction or augmentation of labor?Spontaneous labor more likely to result in successful
VBACSome studies show women with oxytocin
administration undergoing TOLAC may be at increased risk of uterine rupture than spontaneous labor. Other studies have not.
Use of prostaglandins are associated with a higher rate of uterine rupture and are NOT RECOMMENDED
ACOG, 2010
VBAC Success Rates
Induced labor- 67% success rate
Augmented labor-74% success rate
Spontaneous labor-81% success rate
Smith & Merrill, 2006
VBAC Induction
Physician and surgical team must be immediately available throughout active labor
Recommend 1:1 nursing care with an experienced RN
Continuous EFM Must have ability to perform emergency
C/birth
Nursing Implications with VBAC Induction/Augmentation
Access to operating room readily availableMonitor as for high riskSigns and symptoms of uterine
rupture/dehiscence of prior scarPatient c/o increasing pain and tenderness even with
epiduralPresentation may take place over period of time or
suddenly like “something has given away”Vomiting, syncope, vaginal bleeding,
tachycardia, fetal bradycardia or absent fetal heart rate
Management
Maternal stabilization and immediate cesarean birth
Key to diagnosis is suspicion of uterine rupture
Simpson, K.R & Creehan, P., 2001
Conflict? No way!
SummaryEvidence suggests that cervical ripening can
increase the chances of successful inductionMisoprostol (cytotec) is becoming more widely
used for cervical ripening and labor inductionNo elective inductions before 39 completed weeks
of gestationProtocols should be based on ACOG/AHWONN
standards and guidelinesMultiple factors contribute to the steady increase in
the rate of induction in the United StatesConsider implementation of an Induction of Labor
Patient Safety Bundle.
References1. American College of Obstetricians and Gynecologists. (August, 2009). Induction of Labor,
Practice Bulletin, Clinical Management Guidelines for Obstetrician-Gynecologists, Number107. Washington DC: Author.
2. American College of Obstetricians and Gynecologists. (November, 2010). Management of Intrapartum Fetal Heart Rate Tracings, Number116. Washington DC: Author.
3. American College of Obstetricians and Gynecologists. (August 2010).Vaginal Birth After Previous Cesarean Delivery, Practice Bulletin, Clinical Management Guidelines for Obstetrician-Gynecologists, Number115, Washington DC: Author.
4. Simpson, K.R., (2008). Cervical Ripening and Induction and Augmentation of Labor. 3 rd edition. Association of Women’s Health, Obstetric and Neonatal Nurses. Washington DC.
5. American Academy of Pediatrics & American College of Obstetricians and Gynecologists. (2007). Guidelines for Perinatal Care (6th Ed.). Elk Grove, IL, Washington DC: Authors.
6. National Center for Health Statistics (NCHS) year 2000 - 2009 data7. Tita, A.,et al. (2009). Timing of elective preterm and neonatal outcomes. (Electronic Version).
NEJM. 360:2, 111-1208. Joint Commission. (2010). Specifications Manual for Joint Commission Quality Core Measures
http://jointcommission.org/releases/TJC2010A/MIF0166.html9. Phaneuf S., et al, Loss of myometrial oxytocin receptors during oxytocin-induced and oxytocin-
augmented labour. Journal of Reproduction & Fertility 2000;120(1):91-97.10. Glantz, J (April 2005). Elective Induction vs. spontaneous labor Associations and Outcomes.
Ele Med. 50(4):235-240.11. International Classification of Diseases, Code ICD-9-CM Description Shortened Description Table
Number 11.07: Conditions Possibly Justifying Elective Delivery Prior to 39 Weeks Gestation (Ver. 2011A)