NEW YORK, Sept 04 (Reuters) -- Women who have had a cesarean section can go on to give birth to another child vaginally without increasing the infant's risk of complications -- avoiding the minor respiratory problems sometimes associated with an elective cesarean section. However, if the woman tries to deliver vaginally and fails, the infant's risk of infection does increase, according to a report in Pediatrics. But overall, the risk of complications with either mode of delivery is relatively low, the authors said.
Women who have undergone a cesarean section are encouraged to try giving birth vaginally after what is termed "a trial of labor" for a number of reasons, including the fact that a vaginal birth is less debilitating for the mother and costs much less than a surgical birth. The U.S. has one of the highest rates of repeat cesarean sections, making up 38% of all such surgical deliveries.
"Nationally, 70% of mothers who attempt a trial of labor succeed, and the overall maternal and neonatal outcomes are excellent," wrote lead author Dr. Brenda Hook, of the pediatrics department at the University of Texas Health Sciences Center in Houston. More study is needed to find out if there is a way to reduce complications if a trial of labor is unsuccessful, such as turning to surgery at an earlier point if labor is not progressing.
In the new study, Hook and colleagues looked at 497 women who had an elective repeat cesarean section, 336 women who tried labor and succeeded in giving birth vaginally, and 156 who tried labor but needed to have a cesarean section anyway. Those women were compared with 989 women undergoing a routine vaginal delivery.
Infants born after elective cesarean section had more than twice the risk of developing respiratory problems than infants delivered vaginally, including having a short-term bout of tachypnea, or an abnormally fast breathing rate. About 6% of those infants from elective cesarean sections had tachypnea compared with 3% of babies born vaginally.
"For most infants, the respiratory distress was mild and required minimal intervention," the authors wrote. It's not clear why infants delivered by cesarean section have increased respiratory distress, but it may be because a younger gestational age or other factors may play a role.
The infants who underwent cesarean section after unsuccessful labor tended to stay in the hospital longer -- 4.8 days versus 3.1 days -- and were twice as likely to have respiratory illness and 19 times as likely to have an infection as infants who were delivered after a successful trial of labor. However, the infection rate was low with only four infants in the "trial of labor" group having an infection compared with none after cesarean section.
SOURCE: Pediatrics (1997;100:348-353)
