Sometimes I almost feel sorry for natural childbirth advocates. Just about everything they think they know is factually false.
Elective induction is a case in point.
Judith Lothian explained in Saying “No” to Induction:
Saying “no” to induction and to other interventions that are becoming routine takes courage and confidence, as well as the knowledge that women have the right to informed refusal. What women learn from you about nature’s plan for labor and birth, including the beauty of waiting for labor to start on its own and the risks of interfering without clear medical indication, will insure that the women you teach will have the information they need to confidently say “no” to routine induction.
Except that study after study shows that saying “YES” to elective inductions IMPROVES both maternal and neonatal outcomes. A new study, Maternal and neonatal outcomes in electively induced low-risk term pregnancies, comprising 131,243 low-risk births is merely the latest example. As the authors explain:
Several studies have presented information refuting the association of induction with increased cesarean delivery. Two large prospective multicenter studies of late term (41 weeks’ gestational age) pregnancies found no difference or a decreased rate of cesarean delivery in elective inductions vs expectant management. A metaanalysis reported an absolute risk reduction in cesarean delivery rate with elective induction of 1.9% (95% confidence interval [CI], 0.2-3.7%) for late term and post term pregnancies. Similar findings have been reported across different obstetric cohorts, including those with hypertensive disease, fetal growth restriction, and diabetes.
Three recent retrospective analyses found no increase in operative delivery with induction of labor and a decrease in the cesarean delivery rate among nulliparous women delivering at 39-42 weeks’ gestational age and all women delivering in the term period (37-40 weeks). Cheng et al also reported improvement in other associated neonatal morbidities including meconium aspiration, 5-minute Apgar <7, infection, ventilator use, composite morbidity, and neonatal intensive care unit (ICU) admission with induction at 39 weeks’ gestation. Using discharge and birth certificate data, Darney et al also recently found a reduction in cesarean deliveries with induction of labor compared to expectant management at 37, 38, 39, and 40 weeks of gestation. Importantly, Darney et al also reported no increase in neonatal ICU admission or respiratory distress with elective induction of labor, including those performed at 37 and 38 weeks of pregnancy.
The new study confirms these previous studies:
Of 131,243 low-risk deliveries, 13,242 (10.1%) were electively induced. The risk of cesarean delivery was lower at each week of gestation with elective induction vs expectant management regardless of parity and modified Bishop score (for unfavorable nulliparous patients at: 37 weeks = 18.6% vs 34.2%, adjusted odds ratio, 0.40; [95% confidence interval, 0.18-0.88]; 38 weeks = 28.4% vs 35.4%, 0.65 [0.49-0.85]; 39 weeks = 23.6% vs 38.5%, 0.47 [0.38-0.57]; 40 weeks = 32.3% vs 42.3%, 0.70 [0.59-0.81]). Maternal infections were significantly lower with elective inductions. Major, minor, and respiratory neonatal morbidity composites were lower with elective inductions at ≥38 weeks (for nulliparous patients at: 38 weeks = adjusted odds ratio, 0.43; [95% confidence interval, 0.26-0.72]; 39 weeks = 0.75 [0.61-0.92]; 40 weeks = 0.65 [0.54-0.80]).
The authors note:
Using a cohort of low-risk pregnancies within the Consortium on Safe Labor database, we examined maternal and neonatal outcomes for women who were electively induced compared to those expectantly managed at each week of term gestation. For our primary outcome of mode of delivery, we observed a reduction in cesarean section with elective induction, regardless of week of gestation, parity, or cervical examination. For secondary outcomes including maternal and neonatal morbidity, no outcome was shown to be worse with elective induction. Conversely, several maternal outcomes including infectious morbidity, obstetrical lacerations, and shoulder dystocia were reduced with induction of labor. For those electively induced, we observed a reduction in composite neonatal morbidities with induction of labor at 38, 39, and 40 weeks’ gestation. (my emphasis)
How did natural childbirth advocates get it so wrong? They relied on studies that compared induced labor at specific gestational ages with spontaneous labor at the same gestational ages. The correct comparison is induced labor at specific gestational ages vs. waiting (expectant management).
The authors include an important caveat:
…These data do not attempt to define what the best gestational age is for delivery at term. Rather, we submit that our results demonstrate that when maternal and newborn outcomes are analyzed through the prism of the true clinical alternatives of induction or waiting, the findings may be drastically different than what has been reported previously. Clearly, these data suggest that outcomes for mom and baby are complex with competing interests. Evaluations that only consider differences in observed neonatal morbidities by week of delivery paint an incomplete picture as they do not account for the risks of waiting… (emphasis in original)
Poor natural childbirth advocates. Yet again nature does not know best. Mothers who choose inductions for “convenience,” far from increasing their risk of C-section, maternal complications or neonatal complications, may actually be making the safer decision.
