Cervical Ripening

1. Cervical Ripening Renee Crichlow MD,FAAFP North Memorial Residency, Broadway Family Medicine Clinic, “Where Excellence Meets Caring”

2. Objectives • Definition of Cervical Ripening and Induction of Labor • Discuss the indications of Cervical Ripening • Name three methods of Cervical Ripening

3. Name that Tune… • Contractions & Cervical change • Contractions & Cervical change • Contractions & Cervical Change • Contractions & Cervical Change • Contractions & Cervical Change • Contractions & Cervical Change • Contractions & Cervical Change • Contractions & Cervical change

5. Post-term pregnancy PROM PPROM Macrosomia High Net benefits Strong evidence for High Net benefits Strong evidence for Moderate Uncertain trade-offs Weak for Moderate Net harm Weak against “Indications for induction of labor:a best-evidence review” 04/2009 BJOG Volume 116, Issue 5, Pages 626-636

6. Cochrane Reviews • Structured Systematic reviews • One of the original pillars of EBM • Best evidence regarding obstetric practices

8. “Intravenous oxytocin alone for cervical ripening and induction of labor” • “Oxytocin is less effective than prostaglandin to help bring on labor but is as effective when used alone in women with ruptured membranes • Oxytocin is the most common drug used to induce labor and has been used either alone or with rupturing the membranes. • A review of trials found that using PGE2, inserted either via the vagina or cervix, rather than oxytocin was probably more effective. • However, oxytocin alone compared to PGE2 used either way, in women with ruptured membranes, showed that all three methods are probably equally effective. More research is needed. “

10. “Sexual intercourse for cervical ripening and induction of labor” • “The role of sexual intercourse as a method for induction of labor is uncertain. • Human sperm contains a high amount of prostaglandin, a hormone-like substance which ripens the cervix and helps labor to start. • However, there is not enough evidence to show whether sexual intercourse is effective or to show how it compares with other methods. More research is needed” • Many volunteers in our population-- rc

12. “Breast stimulation for cervical ripening and induction of labor” • “Breast stimulation appears beneficial in relation to the number of women not in labor after 72 hours, and reduced postpartum hemorrhage rates. • Breast stimulation causes the womb to contract, though the mechanism remains unclear. • It may increase levels of the hormone oxytocin, which stimulates contractions. It is a non-medical method allowing the woman greater control over the process of attempting to induce labor. • The review found insufficient research to evaluate the safety of breast stimulation in a high-risk population and until safety issues have been fully evaluated “

14. “Castor oil, bath and/or enema for cervical priming and induction of labor” • “More research is needed into the effects of castor oil to induce labor. • Castor oil has been widely used as a traditional method of inducing labor in midwifery practice. It can be taken by mouth or as an enema. • The review of trials found there has not been enough research done to show the effects of castor oil on ripening the cervix or inducing labor or compare it to other methods of induction. • The review found that all women who took castor oil by mouth felt nauseous. More research is needed “

16. “Acupuncture for induction of labor” • “There is insufficient evidence describing the efficacy of acupuncture to induce labor. • Acupuncture is the insertion of fine needles into specific energy points of the body and has been used to help induce labor and reduce labor pains. • The review included three trials involving 212 women. The evidence regarding the clinical effectiveness of this technique is limited, although small studies suggest women receiving acupuncture compared to standard obstetric care received fewer methods of induction. • More research is needed “

18. “Amniotomy alone for induction of labor” • “There is not enough evidence about the effects of amniotomy alone (deliberate rupture of the membranes) to induce labor. • Amniotomy has been used as either the only method of inducing labour if the membranes can be reached, or used with drugs such as oxytocin or prostaglandin. • Amniotomy may be preferred by women wanting a drug-free labor and it is cheap. • However, it can be uncomfortable and, if after amniotomy there is a long time interval before the baby is born, there is a risk of infection. There is also the risk of the cord coming out before the baby. • This review of trials found that there is not enough evidence about the effects of amniotomy alone for the induction of labor “

19. Sweeping of membranes From 38 weeks of pregnancy onwards may not produce clinically important benefit, but does reduce duration of pregnancy and frequency of postdates pregnancy Cochrane Library 2005 Issue 1:CD000451

20. Cochrane Review in Process… “Methods for cervical ripening and labor induction in late pregnancy: generic protocol”

21. “Induction of labor for improving birth outcomes for womenat or beyond term” • A policy of labor induction at 41 completed weeks or beyond was associated with fewer (all-cause) perinatal deaths • There was no evidence of a statistically significant difference in the risk of caesarean section for women induced at 41 and 42 completed weeks respectively. • Women induced at 37 to 40 completed weeks were more likely to have a caesarean section with expectant management than those in the labor induction group • A policy of labor induction after 41 completed weeks or later compared to awaiting spontaneous labor either indefinitely or at least one week is associated with fewer perinatal deaths. However, the absolute risk is extremely small.

23. Cervical ripening, why? Bishop score 6 or higher predicts successful induction and vaginal delivery, if not at >=6, then cervical ripening indicated for achieving dilation

24. Bishop Scoring • Dilation 0 if no dilation, 1 if 1-2 cm, 2 if 3-4 cm, 3 if > 4 cm • Effacement 0 if 0-30%, 1 if 40-50%, 2 if 60-70%, 3 if > 70% • Station 0 if -3, 1 if -2, 2 if -1 or 0, 3 if +1 or +2 • consistency 0 if firm, 1 if medium, 2 if soft • cervical position 0 if posterior, 1 if midposition, 2 if anterior

25. Foley catheter: • Foley catheter - balloon inflated past cervical os • Foley catheter has been used to ripen cervix to inducible Bishop's scores, • 97% effective in study of 88 patients with minimal complication

27. Vaginal misoprostol • In doses above 25 mcg four-hourly was more effective than conventional methods of labor induction, • More uterine hyperstimulation. • The studies reviewed were not large enough to exclude the possibility of rare but serious adverse events, • Rare uterine rupture has been reported anecdotally following misoprostol induction, in women with uterine scarring.

28. “Intracervical prostaglandins for induction of labor” Prostaglandins inserted into the cervix are effective in starting labor, but are inferior to vaginal administration.

29. Head to Head • 588 parous women without prior cesarean section randomized to 1 of 3 groups for labor induction • intravaginal dinoprostone (2 mg once every 6 hours, up to 4 doses) • intravaginal misoprostol (25 mcg once every 4 hours, up to 6 doses) • transcervical (Foley) balloon catheter

30. Head to Head • Comparing dinoprostone vs. misoprostol vs. Foley catheter • mean induction-to-delivery time • 17.3 hours vs. • 16.8 hours vs. • 12.9 hours (p < 0.00001, favoring Foley catheter over both dinoprostone and misoprostol) • no difference in maternal and neonatal outcomes