Labor induction at 32 weeks? Maybe, if your water breaks

In cases of prolonged early membrane rupture, obstetricians must do a careful dance to get the unborn baby as close as possible to term, while avoiding the increased risk of infection. Mothers in this situation are at risk for infection of the membranes surrounding the baby, and such infection can prompt premature delivery or infection of the uterus after delivery. Unborn babies are at risk for a host of infections, including one that can lead to cerebral palsy, from bacteria entering the baby's bloodstream via the membrane rupture.

"The idea is to deliver the mother before the baby gets an infection," says Dr Brost. "The dilemma is trying to deliver later so baby can get older but before an infection can set in."

The study found that infections in both mom and baby were significantly lower in mothers experiencing membrane rupture when they opted for induction at 32 weeks pregnancy rather than waiting for spontaneous labor. In addition, hospital stay for the newborn was considerably shorter in cases where the mother was induced.

"After 32 weeks, it's unusual for a baby to have lifelong problems," says Dr Brost. "If the baby is infected due to the membrane rupture between 32 and 34 weeks, however, the long-term outcome can be worse."

The Mayo Clinic researchers indicate their findings show induction at 32 weeks gestation is an option for women with prolonged premature membrane rupture and their obstetricians to consider to decrease potential infection risk. However, Dr Brost adds that it is important that such induction occur at medical center equipped to care for the premature infant. In order to confirm the study's findings and prompt a change in nationwide standard of care for mothers with premature membrane rupture, the Mayo researchers say their results would need to be replicated in a large study with multiple medical centers. Currently the practice at Mayo Clinic, says Dr. Brost, is to talk to women in this situation about the option of induction at 32 versus 34 weeks.

The Mayo Clinic researchers conducted their study by analyzing a prospectively maintained obstetric database for spontaneous membrane rupture between 24 and 31 weeks gestation between January 1992 and December 2003. They found 408 cases. The investigators examined the experiences of women with premature membrane rupture who were induced at 32 weeks. The experiences of these women were compared against women with early membrane rupture who waited for spontaneous labor and those whose induction became mandatory due to other medical factors.