Just because you are pregnant with twins does not mean you have to plan on having a C-section to maximize your chances of a safe delivery, a new international study shows.
The study of 2,804 women and their babies, published Wednesday in the New England Journal of Medicine, shows that carefully selected moms and babies do equally well whether they and their doctors plan for a cesarean section or plan for a vaginal delivery – and then use surgery only when a vaginal delivery ends up looking too risky.
Those last-minute switches do happen, and women who went for a vaginal birth in the study ended up getting C-sections 44% of the time. But those who planned on C-sections had them 91% of the time (the other 9% went into labor and delivered before a C-section could be done).
Despite the differing surgery rates, the rates of birth injuries, infections, deaths of mothers and babies, and other bad outcomes were the same in the two groups, says lead author Jon Barrett, an associate scientist at the Sunnybrook Health Sciences Center in Toronto.
About 2% of babies and 7% to 8% of mothers in each group had serious complications or died.
Barrett, who is a specialist in maternal-fetal medicine, says many experts expected the study to show that planned C-sections were safer — largely because many second-born twins enter the birth canal in the bottom-down, so-called breech position. Studies show C-sections are best for breech babies in non-twin pregnancies, he says.
But Barrett says he expected planned vaginal births to be just as safe for twins. "I've been doing them for 25 years, and I've never gotten into trouble," he says. One reason, he says, is that well-trained obstetricians can more easily handle a breech birth in a second baby than in a single baby; another, he says, is that part of the plan is switching to a C-section when necessary.
Women were not accepted for the study if so-called "first twins" — those lower in pelvis and expected to be delivered first — were in the breech position after 32 weeks of pregnancy. In those cases and some others where vaginal birth might be risky — comprising about half of twin pregnancies — a planned C-section still is warranted, Barrett says.
The study was conducted in 106 hospitals in 25 countries and included eight hospitals in the United States.
The C-section rate for single births in the United States stands at about 31%, according the Centers for Disease Control and Prevention. But the rate of C-sections for twin births is much higher, about 75% as of 2008. That's up from 54% in 1995, according to an editorial accompanying the study. That increase has been driven in part by less rigorous studies, writes Michael Greene, chief of obstetrics at Massachusetts General Hospital in Boston.
The new study, in which otherwise similar women were randomly assigned to one birth plan or another, provides evidence that a "plan to deliver appropriately selected sets of twins vaginally is a reasonably safe choice in skilled hands," he says.
But Greene also says practice in the United States may not change — partly because there's been a "gradual disappearance" of the skills doctors need to handle breech births or other complicated vaginal births.
He notes that many women also prefer C-sections.