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 laborWhat is augmentation?
Correcting ineffective uterine contractions or hypocontractility
Incidence in the United States
National Center for Health Statistics (NCHS) year 2000 data
Induction of labor- 19.9% labor augmentation-17.9%National Center for Health Statistics (NCHS) year 2009
data Induction of labor - 22.5% Labor augmentation - 19.9%
Since 1989, this represents 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
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
Indications for Cervical Ripening and Induction of Labor
Decrease the rate in patients with elective delivery at 37 to 39 weeks gestation.
Joint Commission National Quality Core Measure PC-01
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 scarACOG 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 CriteriaAvailability 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 continuedConsiderations 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 Consistency Pos 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
Includes documentation of the Bishop score and the presence or absence of uterine activity
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 AgentsThese agents may soften the cervix, change the Bishop score
Mechanical/Non pharmacologic MethodsLaminaria tentsSynthetic hygroscopic dilators (Lamicel and
Dilapan)Balloon cathetersPharmacologic Methods Prostaglandins (E1 & E2)Oxytocin
Mechanical Dilators
Laminaria Tents
Synthetic Osmotic Dilators
Cervical Ripening Balloons
Laminaria Tents
Synthetic Osmotic Dilators• Lamicel • Dilapan
Balloon Catheters and Extraamniotic Saline Infusion
Foley CatheterExtraamniotic saline infusion- balloon
catheterDouble Balloon Cervical Ripening Catheter
Results seen within 8-12 hours after insertion
Mechanical Ripening Devices• Double balloon
device• Foley catheter
Pharmacologic MethodsNot recommended for use in women with
history prior c-birth or uterine scar
Prostaglandin E1: Misoprostol (Cytotec)Oral, sublingual 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
Re-dosing ParametersRe-dosing is permissible if: Still unripe cervix?Happy baby?Redosing is withheld if:
Complications with Misoprostol (Cytotech)
TachysystoleIndeterminate/Abnormal FHR patternPrecipitous LaborsUterine RuptureNeed careful maternal/fetal assessmentsNeed consent/protocols
ACOG, 2009
Prostaglandin E2-DinoprostonePrepidil
Perform speculum exam, introduce gel just below cervical os
Patient should remain recumbent for at least 30 minutes
Uterine contractions usually occur within one hour of administration- peak activity within 4 h
Prostaglandin E2-Dinoprostone
Cervidil
Cervical Ripening AgentsMinimum safe interval from prostaglandin
to oxytocin administration not establishedManufacturers guidelines recommend
Misoprostol- 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 Membranes
AmniotomyArtificial rupture of membranes
• NURSES DO NOT PERFORM AMNIOTOMY
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/minSecond Stage LaborSurge of oxytocin at Ferguson’s reflex
Simpson, KR, 2009
Response to Oxytocin
Oxytocin DosingConsiderable controversy exists about dosage
and rate increase intervals-there is no consensus in the literature
Oxytocin DosingOnly increase oxytocin rate if:FHR is normalLabor has not progressed 0.5 -1 cm/hrContractions are no closer than every 2-3
minutesExcessive 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 DosageStart 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, 1999a, 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 OxytocinAccording to ACOG (2009), protocols that
involve “high-dose” oxytocin are acceptable; however, high-dose oxytocin is associated with more uterine tachysystole
SOGC recommends using the minimum dose to achieve active labor, increasing the dosage no more frequently than every 30 minutes and reevaluating the clinical situation if the oxytocin dosage rate reaches 20 mU/min
Oxytocin and Medication Safety
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 Abruptio placentae
Uterine ruptureHyponatremia (water intoxicaiton)
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
Women attempting VBACShould 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
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 Academy of Pediatrics & American College of Obstetricians and Gynecologists.
(2007). Guidelines for Perinatal Care (6th Ed.). Elk Grove, IL, Washington DC: Authors.2. National Center for Health Statistics (NCHS) year 2000 - 2009 data3. American College of Obstetricians and Gynecologists. (August, 2009). Induction of Labor,
Practice Bulletin, Clinical Management Guidelines for Obstetrician-Gynecologists, Number107. Washington DC: Author.
4. American College of Obstetricians and Gynecologists. (November, 2010). Management of Intrapartum Fetal Heart Rate Tracings, Number116. Washington DC: Author.
5. 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.
6. Association of Women’s Health Obstetric and Neonatal Nurses. (2010). Guidelines for Professional Registered Nurse Staffing for Perinatal Units, Washington DC: Authors
7. Glantz, J (April 2005). Elective Induction vs. spontaneous labor Associations and Outcomes. Ele Med. 50(4):235-240.
8. 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)
9. Joint Commission. (2010). Specifications Manual for Joint Commission Quality Core Measures http://jointcommission.org/releases/TJC2010A/MIF0166.html
10. 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.
11. 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.
12. Tita, A.,et al. (2009). Timing of elective preterm and neonatal outcomes. (Electronic Version). NEJM. 360:2, 111-120