Population: Pregnant women considering induction of labor.
Organizations
NICE 2021, ACOG 2009
Recommendations
–Review risks and benefits prior to deciding on induction. Benefits will vary by indication. Risks (vs. spontaneous labor) include an increased number of vaginal exams, limitations on birth setting, uterine hyperstimulation, increased discomfort and a longer hospital stay.
–Verify gestational age prior to induction. A term gestation is confirmed if an ultrasound completed <20-wk EGA supports current EGA ≥39 wk, fetal heart tones have been documented for >30 wk, or if 36 wk have passed since positive pregnancy test.
–Use prostaglandin (eg, misoprostol, dinoprostone) or1 mechanical cervical dilator (eg, Foley catheter balloon) before oxytocin induction in patients with an unfavorable cervix (typically: Bishop score ≤6).
–Dosing of prostaglandin for ripening:
• Misoprostol: 25 mcg q 3–6 h (may consider 50 mcg q 6). (ACOG: vaginal; NICE: oral) Start oxytocin <4 h after last misoprostol dose.
• Dinoprostone. Give second dose 6–12 h after initial dose if inadequate cervical change; maximum 3 doses in 24 h.
–Oxytocin dosing for induction.
• Low dose: start 0.5–2 mU/min, increase by 1–2 mU/min every 15–40 min.
• High dose: start 6 mU/min, increase by 3–6 mU/min every 15–40 min.
• If uterine tachysystole occurs, decrease or discontinue oxytocin; consider repositioning or administering oxygen and/or IV fluids. If persists, consider tocolytics such as terbutaline.
Practice Pearl
• A 2021 Cochrane Review suggests oral misoprostol may be the best method for cervical ripening. It leads to fewer cesarean deliveries than vaginal dinoprostone or Foley catheter, and higher rates of vaginal birth than dinoprostone. Oral and vaginal misoprostol result in similar vaginal birth rates but oral has lower rates of uterine hyperstimulation and fewer cesarean deliveries for fetal distress. Ideal misoprostol dosing is poorly defined—25 mcg regimens are likely to be best; dosing intervals from q 1 h–q 6 h have been studied without conclusive superiority (https://doi.org/10.1002/14651858.CD014484).
Sources
–Obstet Gynecol. 2009:114(2):386.