The two debaters took different paths but ended up in the same place on the issue about whether elective inductions of labor (IOL) at 39 weeks is a good idea.
Both Charles J. Lockwood, MD, and Errol R. Norwitz, MD, PhD, agreed that mothers with uncomplicated pregnancies should undergo elective IOL at 39 weeks. Neither presenter knew what the other would say during Monday morning’s Edith Louise Potter Memorial Lecture Debate, “If No Elective Inductions Before 39 Weeks, Why Not Induce Everyone AT 39 Weeks?”
Both debaters came to their conclusions separately after preparing for Monday’s session by reviewing the existing literature. Neither one knew where the other stood until after they completed their preparations.
At Tufts University School of Medicine, where Dr. Norwitz is chairman of the Department of Obstetrics and Gynecology and a professor, the saying is, “Think like a fetus.” If a fetus knew that the literature says there’s no benefit for staying in past 39 weeks, and potential risks increase after 39 weeks, wouldn’t the fetus want to be delivered at 39 weeks?
Multiple studies from the United Kingdom and the United States showed that infant mortality risk increases after 39 weeks. Stillbirth rates are at their lowest at 39 weeks and increase significantly after that. The reason is unknown.
“I would argue that continuing a pregnancy beyond 39 weeks is riskier than previously believed for the fetus, and I would argue further that routine induction risks are lower to the mother than previously appreciated,” he said.
He said the major risk factor would be failed induction leading to cesarean. There’s limited data for routine IOL at 39 weeks, but Dr. Norwitz extrapolated data from IOL vs. expectant management (EM) at 41 weeks that showed no increase in cesarean delivery, and possibly a decrease.
Dr. Lockwood, senior vice president, USF Health, dean of the Morsani College of Medicine, University of South Florida, professor of obstetrics and gynecology at Morsani College of Medicine, and professor of health policy and management at the College of Public Health, University of South Florida, admitted that he expected to be against elective IOL at 39 weeks when he started his literature review.
He concluded that — taking into account all outcomes and preferences — elective IOL at 39 weeks was always the superior decision strategy to expectant EM with IOL at 41 weeks.
Dr. Lockwood found that prior observational studies of elective IOL were fundamentally flawed by having spontaneous labor as the control group. That biased results toward lower stillbirth and caesarian delivery rates in the control group by excluding patients with subsequent post-dates and medically indicated IOL.
In addition to reviewing relevant random clinical trials, meta-analysis and population studies, he created a Monte Carlo microsimulation with data based on both randomized and observational studies. Results were similar to what Dr. Norwitz found.
“Elective induction of labor at 39 weeks reduces the number of cesarean deliveries, reduces the occurrence of stillbirth, reduces severe complication rates for infants and reduces severe complication rates for mothers in a very highly statistically significant fashion,” he said.