Women who underwent a Cesarean section for their first delivery encounter more health risks if they try a vaginal birth with their second, Australian researchers said on Tuesday.
The study included more than 2,300 women at 14 hospitals in Australia who were preparing for their second child. About half signed up for a vaginal birth after C-section, or VBAC, and the other half chose to repeat the surgery.
Women who planned a repeat C-section had a significantly lower rate of complications than women who chose to deliver vaginally the second time -- 2.4 percent risk of death or serious complication compared to 0.9 percent in the surgery group.
Similarly, the risk of complications to the mother, such as major bleeding or hemorrhage, was 2.3 percent for women who delivered vaginally compared to 0.8 percent for a planned repeat C-section.
The study, published in open-access journal PloS ONE, aimed to compare women who were eligible to try either option and assess the risks of each.
"Until now there has been a lack of high-quality evidence comparing the benefits and harms of the two planned modes of birth after previous Cesarean," said lead author Caroline Crowther from the Australian Research Centre for the Health of Women and Babies, part of the University of Adelaide.
"The information from this study will help women, clinicians and policy makers to develop health advice and make decisions about care for women who have had a previous Cesarean."
Cesarean births are on the rise worldwide, and they account for nearly a third of all births in Australia. Most second time mothers, some 83 percent, in Australia opt for a repeat C-section the second time around.
Among women in the study who wanted to try a vaginal birth, only 57 percent were able to proceed with it while the rest ended up having C-sections for medical reasons.
While both options presented relatively low risks for women in Australia, the research is likely to convince more women to avoid an attempt at a vaginal birth after C-section, wrote Catherine Spong of the US National Institutes of Child Health and Human Development.
"Mothers are unlikely to choose to await labor regardless of the counseling or the risk to the mother," she said in an accompanying editorial.
"In the end, the onus falls on the clinicians," added Spong, who was not involved in the research.
"Neither the patient nor the clinician would have to fret about whether to attempt a trial of labor or choose a repeat Cesarean if the first Cesarean had been prevented."