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

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 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 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 Agents

These 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-Dinoprostone

Prepidil

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 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 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/min

Second 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

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, 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 Oxytocin

According 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 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

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