Induction of Induction of LaborLabor

C. T. Allred, M.D.C. T. Allred, M.D.

8/7/098/7/09

Standard Maternal Standard Maternal IndicationsIndications

Preeclampsia, eclampsiaPreeclampsia, eclampsia Term premature rupture of Term premature rupture of

membranesmembranes Suspected chorioamnionitisSuspected chorioamnionitis Maternal medical condition (DM, Maternal medical condition (DM,

HTN, renal disease, ht. disease, etc.)HTN, renal disease, ht. disease, etc.) Risk for precipitous deliveryRisk for precipitous delivery Fetal demiseFetal demise

Standard Fetal Standard Fetal IndicationsIndications

Postterm pregnancy (Is it 41 or 42 Postterm pregnancy (Is it 41 or 42 wks?)wks?)

Oligohydramnios (AFI < 5)Oligohydramnios (AFI < 5) IUGRIUGR Rh sensitizationRh sensitization Prior term stillborn infantPrior term stillborn infant Known fetal anomaliesKnown fetal anomalies Not on here is macrosomia, Joe. Not on here is macrosomia, Joe.

More on that in a bit.More on that in a bit.

Preventive Labor Preventive Labor IndicationsIndicationsAMOR-IPATAMOR-IPAT

Active Management of Risk in Pregnancy at Active Management of Risk in Pregnancy at Term.Term. A system that assumes 38 to 41 weeks is the A system that assumes 38 to 41 weeks is the

ideal time to deliver. ideal time to deliver. Days are subtracted from 41 weeks depending Days are subtracted from 41 weeks depending

on the mother’s underlying risk factors. E.G. – on the mother’s underlying risk factors. E.G. – wt. gain > 30 pounds, induce 6 days before 41 wt. gain > 30 pounds, induce 6 days before 41 weeks.weeks.

Relies on confirmation of EDC with US done Relies on confirmation of EDC with US done between 8 and 20 weeks.between 8 and 20 weeks.

Relies on cervical ripening.Relies on cervical ripening. One small study shows section rate of 4%!! One small study shows section rate of 4%!!

(retrospective study)(retrospective study) Not standard of care at this time.Not standard of care at this time.

AMOR-IPAT referencesAMOR-IPAT references Nicholson, J.M., et al, Grand Rounds: Will Nicholson, J.M., et al, Grand Rounds: Will

active management of obstetric risk lower active management of obstetric risk lower C/S rates?, Contemporary OB/GYN, 9/1/05C/S rates?, Contemporary OB/GYN, 9/1/05

Nicholson, J.M., et al, Active Management Nicholson, J.M., et al, Active Management of risk . . . Am J Obstet Gynecol. of risk . . . Am J Obstet Gynecol. 2004:191:616-6252004:191:616-625

Sanchez-Ramos L., et al, Labor induction Sanchez-Ramos L., et al, Labor induction vs expectant management for postterm vs expectant management for postterm pregnancies: a systematic review with pregnancies: a systematic review with meta-analysis. Obstet Gynecol. meta-analysis. Obstet Gynecol. 2003;101:1312-1318.2003;101:1312-1318.

Maternal Maternal contraindicationscontraindications

Placenta previa (complete)Placenta previa (complete) Previous classical c-sectionPrevious classical c-section Uterine scar other than LTCS x 1 Uterine scar other than LTCS x 1 Invasive cervical cancerInvasive cervical cancer Relative contraindications:Relative contraindications:

1 LTCS, narrow pelvis, significant 1 LTCS, narrow pelvis, significant maternal medical conditions (cardiac, maternal medical conditions (cardiac, pulmonary, neuro), polyhydramnios, pulmonary, neuro), polyhydramnios, grand multiparitygrand multiparity

Fetal contraindicationsFetal contraindications

Active maternal genital herpesActive maternal genital herpes Untreated maternal HIVUntreated maternal HIV Transverse lieTransverse lie Vasa previaVasa previa Severe IUGR with abn. Doppler studiesSevere IUGR with abn. Doppler studies Significant hydrocephalusSignificant hydrocephalus Specific nonreassuring FHT patternsSpecific nonreassuring FHT patterns Relative: presenting fetal part above Relative: presenting fetal part above

the inletthe inlet

Risk of inductionRisk of induction

Unintentional preterm deliveryUnintentional preterm delivery To infer fetal maturity (ACOG) – To infer fetal maturity (ACOG) –

ultrasound measurement before 20 ultrasound measurement before 20 weeks supports gestational age of > or weeks supports gestational age of > or = 39 weeks.= 39 weeks.

FHTs documented as present for 30 FHTs documented as present for 30 weeks by doppler.weeks by doppler.

>36 weeks since a positive urine or >36 weeks since a positive urine or serum HCG serum HCG

Risk of inductionRisk of induction

ACOG Practice Bulletin, # 107, 8/09ACOG Practice Bulletin, # 107, 8/09

Nulliparous women Nulliparous women with unfavorable with unfavorable cervices should be cervices should be counseled about a counseled about a TWO FOLD increased TWO FOLD increased risk for c-section risk for c-section

Risk of inductionRisk of induction

Requires continuous electronic fetal Requires continuous electronic fetal monitoring.monitoring.

Most agents carry the risk of Most agents carry the risk of tachysystole leading to tachysystole leading to nonreassuring fetal heart patterns.nonreassuring fetal heart patterns.

Rupture of membranes > 12 hours Rupture of membranes > 12 hours increases risk of maternal and increases risk of maternal and neonatal infection.neonatal infection.

Risk of inductionRisk of induction

All of these factors need to be All of these factors need to be discussed with the mother prior to discussed with the mother prior to induction as well as alternatives and induction as well as alternatives and those risks.those risks.

Document!Document!

Factors predicting Factors predicting successsuccess

Bishop score > 5 to 7. Dilation is Bishop score > 5 to 7. Dilation is most important factor.most important factor.

Gestational age.Gestational age. Multiparity.Multiparity. Lack of factors leading to large Lack of factors leading to large

baby/uteroplacental insufficiencybaby/uteroplacental insufficiency

Cervical ripeningCervical ripening

Leads to an Leads to an increased increased likelihood of likelihood of successful successful induction if Bishop induction if Bishop > 5 in multips, > 7 > 5 in multips, > 7 in primips.in primips.

Multiple methods:Multiple methods: Membrane Membrane

strippingstripping AmniotomyAmniotomy MechanicalMechanical Breast stimulation Breast stimulation

(not recommended)(not recommended) ProstaglandinsProstaglandins OxytocinOxytocin

Amniotic membrane Amniotic membrane strippingstripping

Works to cause spontaneous labor and Works to cause spontaneous labor and decrease the need for induction. Shortens decrease the need for induction. Shortens pregnancy by 3 days.pregnancy by 3 days.

NNT = 8 to prevent one induction.NNT = 8 to prevent one induction. Sweep by placing finger(s) through the cervix Sweep by placing finger(s) through the cervix

and freeing the membranes from the uterus in and freeing the membranes from the uterus in a circular pattern.a circular pattern.

Begin at 38 weeks and do weekly.Begin at 38 weeks and do weekly. Hurts, can cause SROM, prolapse of cord, Hurts, can cause SROM, prolapse of cord,

promotion of infection, bleeding. (Only the promotion of infection, bleeding. (Only the first and last are common.) Discuss with pt. first and last are common.) Discuss with pt. first!first!

MechanicalMechanical

Foley # 16 with tip removed through the Foley # 16 with tip removed through the cervix. Inflate with 30 to 80 cc of water.cervix. Inflate with 30 to 80 cc of water.

Retract so it rests against the internal os. Retract so it rests against the internal os. Some attach to a liter of saline and Some attach to a liter of saline and suspend from the end of the bed. Not suspend from the end of the bed. Not shown to improve success.shown to improve success.

It works to improve Bishop score and It works to improve Bishop score and decrease time to delivery.decrease time to delivery.

Can cause AROM, injury to placenta, Can cause AROM, injury to placenta, pain.pain.

ProstaglandinsProstaglandins

PGE1 – misoprostol. Optimal dose PGE1 – misoprostol. Optimal dose appears to be 25 micrograms q 3 to 6.appears to be 25 micrograms q 3 to 6. 50 works but seems to increase 50 works but seems to increase

tachysystole more than 25.tachysystole more than 25. 100 microgram pill = $1.100 microgram pill = $1. Works. Improves Bishop score and Works. Improves Bishop score and

decreases time to delivery.decreases time to delivery. Associated with more FHT abnormalities Associated with more FHT abnormalities

and thick meconium than PGE2.and thick meconium than PGE2.

ProstaglandinsProstaglandins

PGE2 – dinoprostonePGE2 – dinoprostone Prepidil – vaginal gel. .5 mg q 6-8 hours to Prepidil – vaginal gel. .5 mg q 6-8 hours to

max of 3 doses.max of 3 doses. Cervidil – vaginal insert. 10 mg pladget Cervidil – vaginal insert. 10 mg pladget

inserted in vagina x 12 hours. Not approved inserted in vagina x 12 hours. Not approved for use > 1 x, but some do. Advantage is has for use > 1 x, but some do. Advantage is has a string and can pull if tachysystole and FHT a string and can pull if tachysystole and FHT problems.problems.

Both seem to be gentler than misoprostol.Both seem to be gentler than misoprostol. Both work. Cost > 100 x more than Both work. Cost > 100 x more than

misopros.misopros.

InductionInduction

Misoprostol can be used q 3 to 6 hours Misoprostol can be used q 3 to 6 hours for induction. Is effective but increase for induction. Is effective but increase in tachysystole and thick meconium.in tachysystole and thick meconium.

PitocinPitocin Effect after 5 minutes but steady state is Effect after 5 minutes but steady state is

reached in 40 minutes.reached in 40 minutes. High dose vs. low dose: both work. High High dose vs. low dose: both work. High

dose accomplishes delivery faster with dose accomplishes delivery faster with more FHT problems but equal outcomes. more FHT problems but equal outcomes.

SRHC – Smoky HillSRHC – Smoky Hill

Baseline FHT tracing. Is it reactive? Baseline FHT tracing. Is it reactive? What is variability?What is variability?

Pitocin 10 units in 500 ml Normal Pitocin 10 units in 500 ml Normal Saline, 1 mu/3ml. (Triple Saline, 1 mu/3ml. (Triple concentration when reach 36 mu/min concentration when reach 36 mu/min – makes for 1 mu/ml)– makes for 1 mu/ml)

Increase gradually to achieve 3 to 5 Increase gradually to achieve 3 to 5 contractions over a 10 minute period. contractions over a 10 minute period. If the cervix is changing > 1 cm/hr, If the cervix is changing > 1 cm/hr, you do not need to increase the pit!you do not need to increase the pit!

Tips for a successful Tips for a successful inductioninduction

Know your dates.Know your dates. Ripen the cervix. If not > 5-7, Ripen the cervix. If not > 5-7,

consider continued ripening.consider continued ripening. Be patient. Do not consider the Be patient. Do not consider the

induction a failure until the pt. is induction a failure until the pt. is through the latent phase (cx at least through the latent phase (cx at least 4 cm)4 cm)

AROM early if committed. AROM early if committed.