1-18-2001

Contact: Andrew Matejcic
amatejcic@cihr.ca
613-954-7143
Canadian Institutes of Health Research

Study finds breech babies three to four times safer if delivered via caesarian section

TORONTO-- A study funded completely by the Canadian Institutes of Health Research (CIHR), which has been fast tracked for publication in The Lancet, has proven that in the case of full term breech presentation, the safest method of delivering babies is via caesarian section.

Dr. Mary Hannah, Professor of obstetrics and gynecology at Sunnybrook and Women's College Health Sciences Centre, University of Toronto, and a senior researcher at the Centre for Research in Women's Health led the study, which included 2,088 women from 121 hospitals in 26 countries. The study was supposed to last for five years but stopped two years earlier than expected due to an interim analysis that showed major benefits for babies randomized to the caesarian section group compared to the vaginal birth group.

Overall, the study found that babies of women in the caesarian section group were three to four times less likely to die or have serious problems in the first six-weeks of life compared to those in the vaginal birth group (1.6% vs. 5.0%). The benefits from a planned caesarian section were greater in centers in developed countries with the difference in risk of death or serious problems for the baby being 0.4% vs. 5.7%, compared to the difference in centers in developing countries 2.9% vs. 4.4%. There was no difference in problems for the mother in the two groups regardless of whether the woman delivered in a developed or developing country, and the overall risk was low (less than 4%).

"It was our concern that vaginal births would disappear as an option when babies presented in the breech position as the more skilled clinicians left the profession. If it was true that planning for a caesarian section was not substantially better than planning for a vaginal birth and research were to prove this, then we felt that the move towards more caesarian sections might stop," says Dr. Hannah. "When we conducted the interim analysis we were surprised to see that a policy of planned caesarian section was substantially better for the baby in a breech presentation at term, and when all the data were analyzed, the benefit was found to be greatest in developed countries such as Canada and the United Kingdom."

In total, the worldwide $2.3 million study concluded that 14 additional caesarian sections are needed to avoid one death or serious problem for the baby. For centers in developed countries an additional seven caesarian sections would be needed to avoid one death or serious problem for the baby. For centers in developing countries an additional 39 caesarian sections would be needed to avoid one death or serious problem for the baby.

"Dr. Hannah's ground-breaking, innovative work reinforces CIHR's dedication to supporting Canada's best clinical researchers," said Dr. Alan Bernstein, President of CIHR. "Her research will have global implications in the health research arena and that's what CIHR is all about."

"Caesarian section is generally associated with a higher risk of problems for the mother than vaginal birth," Dr. Hannah says. "However, in the Term Breech Trial there was no benefit to the mother of a planned vaginal birth possibly because about 43% of mothers in that group ultimately delivered by caesarian section and because the caesarian sections done in that group were usually done after labor began, on an emergency basis. Whereas, many of the caesarians in the planned caesarian section group were undertaken prior to labor, on an elective basis. Also, we only have information about serious problems in the first six weeks postpartum. A follow-up component of the study is in progress that will give us additional information about the health of mothers at three months and two years postpartum."

In Canada, about 12,000 - 16,000 women will deliver a baby in breech presentation at term every year.

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