Lively Debate Over Cesarean Risk After Induction of Labor

Tara Haelle

May 04, 2018

AUSTIN — Recent evidence casts doubt on the long-held belief that induction of labor increases the risk for cesarean delivery, said Aaron Caughey, MD, PhD, chair of the Department of Obstetrics and Gynecology at the Oregon Health & Science University in Portland.

However, because culture and labor-floor management are different at different institutions, providers need to carefully assess the evidence before establishing the practices that will lead to the best outcomes at their hospital.

"There are no simple answers," Caughey said here at the American College of Obstetricians and Gynecologists (ACOG) 2018 Annual Meeting, where he discussed the myths, facts, and misconceptions about the induction of labor.

It's time for long conversations, and probably some struggles, about the benefits and risks of induction of labor after 39 weeks, he explained.

The elective induction of labor before 39 weeks is inconsistent with ACOG recommendations and the standard of care. But once a woman reaches 39 weeks, clinical judgment and institutional culture end up playing a substantial role in the decision to induce.

Caughey described the ARRIVE trial (NCT01990612), which made waves when it was presented at the Society for Maternal-Fetal Medicine's 38th Annual Pregnancy Meeting earlier this year, as reported by Medscape Medical News.

ARRIVE Trial Controversy

The 6106 ARRIVE participants — all at 39 weeks to 39 weeks and 4 days of gestation — were randomized to induction of labor or expectant management.

Cesarean deliveries were less common in the induction group than in the expectant management group (18.6% vs 22.2%), as were pre-eclampsia or gestational hypertension (9.1% vs 14.1%). Other outcomes were comparable or nonsignificant.

Infant outcomes were similar in the two groups, except the need for respiratory support within the first 72 hours was lower in the induction group than in the expectant management group (3.0% vs 4.2%). Previous research has shown that the composite risk for perinatal death begins to increase with expectant management around 39 weeks.

But these findings — from one not-yet-published study — should be interpreted with caution, Caughey said.

The bottom line is that there's an increasing body of evidence to suggest that our bias that induction of labor increases the risk of cesarean delivery is not true.

Prospective randomized controlled trials have shown lower rates of cesarean delivery with the induction of labor. And although some retrospective studies have shown higher rates, other retrospective studies, using appropriate comparison groups and statistical adjustment, have shown no difference or slightly lower rates.

But providers should not necessarily start offering every woman past 39 weeks an elective induction of labor.

"We should not be saying to women, 'we might save your baby's life by delivering at 39 weeks'," Caughey explained. "That would be incredibly over-reaching from the data. It would cause chaos and mayhem."

Even if the ARRIVE results are published and replicated, providers must consider other factors, he pointed out.

"Can you imagine today if you started offering elective inductions of labor" to every woman past 39 weeks? he asked. "What would happen if your labor floor is full of women being electively induced at 39 weeks and someone comes in with a VBAC and has to be turned away?"

Evidence on late-term induction of labor is evolving, so clinicians — when deciding when to offer inductions — need to weigh maternal preferences, risk for maternal complications, risk for neonatal complications, risk for cesarean delivery, overall costs, labor-floor management, and the differences between research protocols and actual practice.

"The bottom line is that there's an increasing body of evidence to suggest that our bias that induction of labor increases the risk of cesarean delivery is not true," Caughey told Medscape Medical News. "That being said, there are many practice settings where it might, so you have to take those data, go back to your home institution, and have tough conversations with other providers about your local culture and how you practice."

Consistent, Equitable Care

If it is determined that induction is unlikely to increase cesarean delivery rates at a particular institution, those providers need to figure out if and how they will offer induction of labor to women at 39 weeks to 40 weeks and 6 days of gestation, which is still considered elective.

"Would you offer it? Would you honor their preferences? Would you create a queue?" he asked. "You have to create a local policy so that there can be consistent, equitable care for all individuals."

Caughey's presentation is the type of lecture that brought Anna Wouters, MD, an ACOG Junior Fellow from St. Petersburg, Florida, to the meeting.

"You have new trials coming out that are changing paradigms that have existed for 10 and 15 years," Wouters told Medscape Medical News. "We think we know that inducing labor is going to increase your C-section risk, and that's how we're counseling patients. Then suddenly this new trial comes out that flies in the face of that."

When patients read the headlines and come in asking for induction at 39 weeks, providers need to think about how to balance risks and benefits for that patient, she pointed out.

"This is the entire reason you come to a conference like this — to have these types of conversations and discuss how we're going to move forward in this challenging environment," she added.

Although the presentation was an excellent guide for clinicians, there are limitations when evidence comes from populations of predominantly white women, said Carmen Thornton, MD, an obstetrician–gynecologist in Houston.

"What my concerns are, as a woman of color, is that most of the information that gets us to these recommendations does not really look at differences such as race and ethnicity," Thornton told Medscape Medical News.

The prevalence of type 2 and gestational diabetes is high in the Latina population, which makes up a large proportion of Thornton's patients. And rates of morbidity and mortality are high among black mothers, she added.

"Clearly there's room for improvement," she said. "We need to take a deeper dive and find the information that allows us to learn more. Is there something we can do differently for these populations of women to get to the end result of a healthy mom and healthy baby?"

The presentation was "outstanding," said Howard Blanchette, MD, professor and chair of Department of Obstetrics and Gynecology at New York Medical College and chief of obstetrics and gynecology at Westchester Medical Center in Valhalla, New York.

"It really helped all of us understand what our role as healthcare providers is in terms of the safety of the mother and the baby in the process of induction of labor," Blanchette told Medscape Medical News.

"For many of the people here, this was very enlightening and helpful for when they go back to take care of their patients," he pointed out. "You have to take the best evidence you have, but in the end, it's up to your clinical judgment, your experience, and your ability to communicate effectively with your patient in terms of what the optimum care for both her and her baby is."

Caughey reports being a consultant and serving on the advisory board for Celmatix, and serving on the clinical advisory board for MindChild, where he holds ownership interest. Thornton and Blanchette have disclosed no relevant financial relationships.

American College of Obstetricians and Gynecologists (ACOG) 2018 Annual Meeting. Presented April 28, 2018.

Follow Medscape OBGYN on Twitter @MedscapeObGyn and Tara Haelle @TaraHaelle

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