After first cesarean, risks go up in next pregnancy

Adverse outcomes in the next birth are more common among women who deliver their first child by cesarean section than those who deliver their first child vaginally, according to a new report.

"Women who request elective caesarean section for no medical indication should be aware of these potential increased risks for themselves and their babies in their next and future births," Robyn Kennare, a midwife with the Department of Health, Adelaide, South Australia, told Reuters Health.

Kennare and colleagues estimated the association between cesarean delivery of a first child and adverse outcomes in the birth of a second child using data collected between 1998 and 2003 for the second pregnancies of 8,725 women who previously underwent cesarean section and 27,313 women who previously delivered vaginally.

They found that the risks of a whole host of problems including bleeding, prolonged labor, malpresentation, ruptured uterus, and emergency cesarean, were significantly higher among women who delivered by cesarean section in their first pregnancy than among women who first delivered vaginally.

Infants in the cesarean group were also more likely to be preterm (before 37 weeks' gestation) or very preterm (before 32 weeks' gestation), small for gestational age, low birth weight or stillborn, compared with infants in the vaginal group.

However, previous cesarean delivery was not associated with increased risk of death of the newborn, the report indicates.

"Although the absolute risks of many of the outcomes are not high, some of the outcomes are very serious ones or may have very serious consequences," Kennare said.

SOURCE: Obstetrics and Gynecology, February 2007.