Reduced fertility after C-section often by choice

NEW YORK (Reuters Health) - Women are less likely to bear another child following a cesarean delivery than after a normal vaginal birth, Norwegian researchers found in a study. However, they also found evidence that lower fertility after a c-section is "probably to a large degree voluntary and not related to the indication, nor to any physical consequence, of the cesarean delivery."

Dr. Mette C. Tollanes at the University of Bergen and associates analyzed data on 596,000 healthy women who delivered their first child during 1967-1996 and were followed up through 2003. They excluded women with multiple pregnancies, women whose partner changed between pregnancies, and those who died before age 50.

Delivery by Cesarean section was associated with a significantly reduced risk of a second birth in comparison to vaginal deliveries, Tollanes and colleagues report in this month's issue of Obstetrics and Gynecology.

However, if the child was stillborn or died during the first year, cesarean delivery was no longer associated with a lower likelihood of having a second child. This suggests that c-section per se does not reduce fertility, but that it is associated with choosing to have fewer children.

The research team notes that cesareans are still increasing in many developed countries. "In a country such as the United States, where the cesarean delivery rate in 2004 was almost twice as high as in Norway (29.1 percent compared with 15.4 percent), cesarean delivery could have a substantial overall effect on reducing fertility," they add.

SOURCE: Obstetrics and Gynecology, December 2007.