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MS WordPerinatologist Corner - C.E.U/C.M.E. Modules
Post-term Pregnancy and Induction of Labor
Sponsored by The Indian Health Service Clinical Support Center
4 Management
Case 3
Angela Redfox is a 32 y/o G5P4 at 42 weeks 3 days by an unsure last menstrual period. She has not had any prenatal care to date and presents to your level I facility that provides obstetric care. She is in active labor with moderately strong contractions occurring every 3 minutes. The cervix is 5 cm dilated, 80% effaced, cephalic with the presenting part at 0 station. SROM occurs during your exam producing thick meconium. The fetal heart rate tracing reveals somewhat diminished beat to beat variability; some contractions are accompanied by deep variable decelerations. What is your best plan of action for her at this point?
Due to the above risks associated with post-term pregnancy, ACOG recommends induction of labor in the 43rd week (after 42 weeks). Factors impacting the decision to induce involve:
- patient’s wishes
- dating criteria for that pregnancy
- fetal well being is assured by antenatal testing
- favorability of the cervix.
The decision is easier if there is evidence of fetal jeopardy and/or the cervix is favorable.
Cervical favorability
The 2002 Cochrane review did not find that breast or nipple stimulation at term significantly affected the incidence of post-term pregnancy (OR=0.52 [CI: 0.28-0.96]), presumably reflecting that this practice did not reliably result in spontaneous labor. (Crowley P – Cochrane Library
)
Stripping (or “sweeping”) the membranes has been demonstrated in 2 small studies to be associated with a decreased incidence of postdate gestation, but Boulvain et al
found it may not produce clinically important benefits consistently in a Cochrane review.
There is evidence that the use of various prostaglandin preparations does increase cervical Bishop scores and the incidence of persistent contractions that result in inducing labor. Nevertheless, their use does not necessarily translate into a decrease in the cesarean delivery rate. There is to date no standardized preparation or dose demonstrated to be superior for this purpose. (The various preparations and their appropriate use will be detailed further below.)
The cervix with a Bishop score <4 is considered highly unfavorable because of the high incidence of failed induction, and women with such an “unripe” cervix are often managed with antenatal fetal testing.
