Preinduction cervical ripening with the Foley catheter and the risk of subsequent preterm birth

The Foley catheter is a safe and effective form of preinduction cervical ripening and is quickly growing in popularity. Its major effect appears to be through mechanical dilation, which has raised the concern that the use of the Foley catheter for cervical ripening may damage the cervix and result in a higher rate of subsequent preterm birth.

We conducted a review of all induction of labor at our institution from July 1998 to July 2001 that required preinduction cervical ripening and had a subsequent birth. The primary outcome variable was preterm birth at <35 weeks of gestation. Demographic and potential confounding variables were analyzed. A probability value of <.05 was considered significant.

The cases of 126 women (63 women in the Foley group and 63 women in the prostaglandin group) were studied. Women in the prostaglandin group had a prostaglandin agent used. There was no difference in maternal age, gravidity, parity, Bishop score, total time of induction, gestational age, oxytocin use, maximum oxytocin level, tobacco or drug use, or type of delivery in the index pregnancy between the groups. In the subsequent pregnancies, there were no differences in maternal age, gravidity, parity, spontaneous abortions, terminations, cone or Loop Electrosurgical Excision Procedure (LEEP) procedures, history of cervical manipulation, tobacco or drug use, stillbirth, need for induction, mode of delivery, episiotomy, gestational age at delivery, Apgar scores, labor duration, use of oxytocin, or birth weight. There were no differences in preterm birth at 37, 35, or 32 weeks of gestation between the groups.

The use of the Foley catheter for preinduction cervical ripening does not appear to increase the risk of preterm birth in a subsequent pregnancy.