NEW YORK (Reuters Health) – Contrary to common belief, a systematic review has found that elective induction of labor at or beyond 41 weeks of gestation may reduce cesarean section rates and the occurrence of meconium-stained amniotic fluid.

Since much of the supporting data is from observational studies, however, the authors conclude that more research is needed before the findings can be applied to “real world” practice.

Rates of labor induction, including elective induction, are on the rise, but whether this has translated into improved outcomes or greater complications and costs is often debated, Dr. Aaron B. Caughey, from the University of California, San Francisco, and colleagues state.

Searching MEDLINE, the Cochrane Central Register of Controlled Trials, and other sources, the authors ultimately identified 36 articles that met inclusion criteria, including 11 randomized controlled trials and 25 observational studies. In all cases, labor was induced at or beyond 39 weeks of gestation, according to the report in the Annals of Internal Medicine for August 18.

Expectant management of pregnancy was associated with a 22% increased risk of c-section compared with elective labor induction, the report indicates. The absolute risk difference was 1.9 percentage points.

Further analysis showed that the association between elective induction and a reduced c-section rate was only statistically significant in women at or beyond 41 weeks of gestation (OR = 1.21).

Expectantly managed women were also twice as likely as those who underwent elective labor induction to have meconium-stained amniotic fluid, the authors note.

The rise in elective inductions “may not be as bad as obstetricians have traditionally believed,” Dr. George A. Macones, from Washington University in St. Louis, comments in a related editorial. “I hope that Caughey and colleagues’ excellent systematic review will spur obstetricians to rethink and, more important, to more carefully research the role of elective induction of labor at and beyond 39 weeks.”

Reference:
Ann Intern Med 2009;151:252-263,281-282.