OBJECTIVE:

To evaluate maternal and neonatal outcomes associated with birth at term by week of gestational age and also by onset of labor.

DESIGN:

Cohort study.

SETTING:

A state-wide perinatal outcome database.

POPULATION:

28,626
women with spontaneous onset of labor, induction of labor for
recognized indications and induction of labor for non-recognized
indications.

METHODS:

Cohort study utilizing a validated dataset comparing outcomes with type of onset of labor using a log binomial model.

MAIN OUTCOME MEASURES:

Cesarean section, assisted vaginal birth, important measures of maternal and neonatal morbidity.

RESULTS:

Induction
of labor for non-recognized indications was associated with a
significantly increased risk of a range of outcomes, including cesarean
section (RR 1.67, 95% CI 1.55-1.80). The lowest risk of adverse maternal
and infant outcome occurred with birth between 38 and 39 weeks and with
the spontaneous onset of labor.

CONCLUSIONS:

Induction
of labor for non-recognized indications at term is associated with an
increased risk of adverse outcomes. Caution is warranted with a liberal
policy of induction of labor at term in an otherwise uncomplicated
pregnancy.