Women who deliver their first child by Cesarean section are significantly less likely have another pregnancy compared with women who have an initial vaginal delivery, according to researchers.

Dr. Jill Mollison, of the University of Aberdeen, UK, and colleagues studied women who had delivered their first child in Aberdeen Medical Hospital between 1980 and 1997. The team obtained data on the first and the next pregnancy from the Aberdeen Maternity Neonatal Databank, and compared subsequent pregnancy by three delivery groups.

Data from 25,371 women were included in the analysis, which is published in the British Journal of Obstetrics and Gynecology.

Women who delivered by Cesarean section were less likely to have a subsequent pregnancy than those who delivered vaginally, either spontaneously or with the assistance of obstetrical instruments. This finding confirmed those from a previous study on an earlier group from the same population.

All of the women were followed for a minimum of 5 years. Women who delivered by Cesarean section had the longest time to next pregnancy compared with instrumental and spontaneous vaginal delivery. In contrast to the earlier study, the likelihood of a subsequent pregnancy following instrumental vaginal delivery was similar to spontaneous vaginal delivery.

“These data do not allow us to suggest that fertility is compromised following Cesarean section or whether the difference in subsequent pregnancy is due to voluntary factors,” Mollison’s team notes.

The authors explain that the experience of Cesarean section and the circumstances surrounding it may be enough to lead to avoidance of further pregnancies.

SOURCE: British Journal of Obstetrics and Gynecology, August 2005.