A study published in the New England Journal of Medicine (NEJM) on October 3rd examines what is safer for the delivery of twins: planned vaginal or planned cesarean section? A summary of the study was written by the Associated Press and distributed widely through many news outlets, including National Public Radio. The title of the AP article—“Most Twins Can Be Born Without a C-Section”—gets at the major finding of the study. The authors randomly assigned women with twin pregnancies between 32 weeks 0 days gestation and 38 weeks 6 days gestation and with the first twin in a head-down (cephalic) position to planned cesarean section (1398 women) or planned vaginal delivery (1406 women). There was no significant difference in outcomes between these two groups. That is, a planned vaginal twin delivery posed no greater risk to women and babies than a planned cesarean section twin delivery.
This study is notable. As the authors of the NEJM study observe, the rate of vaginal twin delivery has plummeted in recent years. There is no doubt that part of this decrease is due to publication of findings from The Term Breech Trial, which discovered worse outcomes for babies presenting in breech (head up) position who were delivered vaginally. Although in a follow-up study published in 2004 the outcomes at age 2 of the babies born vaginally were no different from the outcomes at age 2 of babies born by c-section, planned vaginal breech delivery had already been greatly curtailed worldwide.
The Term Breech Trial affected twin deliveries because many second twins (i.e. the twin that is delivered second) present in a breech position. Although the Term Breech Trial only included singleton pregnancies, maternity clinicians I interviewed for the research in my book indicated that many obstetricians stopped offering vaginal twin deliveries when the second twin was presenting in a breech presentation because, with the publication of findings from the Term Breech Trial, if there were to be a bad outcome, they believed they would be sued for malpractice. The NEJM study published on October 3rd, which includes five of the authors of the Term Breech Trial publications, is a good redress to obstetricians’ defensive practice of delivering most twins by c-section.
This study is good news for women pregnant with twins. If vaginal delivery is not being presented to them as an option, they should bring this publicly available article to their next prenatal appointment.
Theresa Morris is Professor of Sociology at Trinity College in Hartford, Connecticut. She is the author of Cut It Out: The C-Section Epidemic in America (NYU Press, October 2013).