Induction of labor in the nineties: conquering the unfavorable cervix.

OBJECTIVE: To determine the efficacy, safety, and duration of induced labor using an integrative approach (prostaglandin, amniotomy, oxytocin) and to depict these findings graphically.

METHODS: Five hundred ninety-seven pregnancies requiring induction of labor between October 1993 and May 1995 were analyzed prospectively. Patients were categorized by Bishop score at entry and by parity for comparison of success of induction, maternal and fetal complications, and duration of labor.

RESULTS: The women who had a Bishop score at entry of 3 or less had significantly higher rates of failed induction (9.4 versus 0.7%, P < .01) and of cesarean delivery (29 versus 15.4%, P < .01) than those with a Bishop score above 3. Compared with spontaneous labor, the rates of cesarean delivery in induced labor remained significantly elevated. Complications of induction were infrequent, regardless of Bishop score. The time from initiation of induction to achievement of active phase was significantly longer in women with lower Bishop scores.

CONCLUSION: Regardless of cervical status and parity, vaginal delivery can be anticipated in the majority of patients undergoing labor induction. The induction characteristics described may assist in the management of induced labor.