Twins Jordyn and Coby Sargon

Jessica Kudlats gave birth to twins Jordyn and Coby Sargon by C-section three years ago. (Courtesy Jessica Kudlats)

Giving birth to twins vaginally is equally safe for both the babies and mothers compared with caesarean section deliveries, according to a large, Canadian-led study.

The Twin Birth Study published in Wednesday's online issue of the New England Journal of Medicine is a 10-year trial that randomly assigned 2,800 women, including 260 in Canada, to either vaginal or caesarean births for twins in uncomplicated pregnancies.

"There does not seem  to be any advantage to the baby by doing a planned caesarean section," said Dr. Jon Barrett, the study's principal investigator and chief of maternal-fetal medicine at Toronto's Sunnybrook Health Sciences Centre.

"To be honest, that's why most women and practitioners were tending to chose caesarean section  because they thought that caesearean section was safer," he said. 

The study was designed to look for differences in deaths and severe complications among the babies, such as brain or spinal cord injury. Deaths and major complications in the mothers, such as need for hysterectomy and major blood loss, were also tracked.

The researchers found 60 deaths or major complications among infants in the planned C-section group, 2.2 per cent, compared with 52 or 1.9 per cent in the planned vaginal group. Statistically, that amounts to no difference, meaning planned C-sections aren't safer or riskier than planned vaginal births.

To be eligible for the study, the pregnancies needed to be uncomplicated, with the first twin in cephalic or head-first position, the pregnancy was between 32 weeks and 38 weeks and six days of gestation, and both fetuses alive with an estimated weight of between 1,500 grams and 4,000 grams based on ultrasound estimates a week before the randomization.

Currently in Canada, between 60 and 80 per cent of twins are delivered by C-section. Barrett hopes the findings will reverse reliance on C-sections. That will require obstetricians to preserve their skills in performing vaginal deliveries of twins, he said.

Of the planned C-sections, 90 percent ended up being C-sections. Of the planned vaginal deliveries, 56 percent were vaginal for both twins. 

Planning C-sections

Dr. Michael Greene of the department of obstetrics and gynecology at Massachusetts General Hospital in Boston applauded the massive logistical effort it took to conduct the trial.

"Obstetricians exercising their best clinical judgment delivered both twins by caesarean section in nearly 40 per cent of the women assigned to planned vaginal delivery, which undoubtedly contributed to the salutary outcomes," Greene said in a journal commentary accompanying the study.

"However, the results of this study suggest that a plan to deliver appropriately selected sets of twins vaginally is a reasonably safe choice in skilled hands."

Twins still need to be delivered by C-section in some circumstances, such as if the first twin is in a breech position or the babies are very premature, Barrett said.

Jessica Kudlats, 37, of Toronto, was eligible to birth to her twins vaginally three years ago. She chose C-section. After speaking with friends who had vaginal births for single babies, she now regrets the decision.

"I never experienced the birthing process," Kudlats said.

Kudlats said other friends who gave birth to twins planned for C-sections. "A lot of people, it's the fear of the unknown," she said of their motivation. "They want everything lined up."

Kudlats said she was in a lot of pain and unable to move to care for her son, Coby, and daughter, Jordyn, shortly after the births.

The study was funded by the Canadian Institutes of Health Research.

With files from CBC's Kas Roussy