Using a balloon catheter to ripen the cervix* in preparation for labor induction results in similar rates of cesarean, chorioamnionitis (inflammation of the fetal membranes), and low Apgar scores, and as with misoprostol, the cost is low.
A Swedish study compared outcomes between 314 women who had cervical ripening with balloon catheter and 274 women who had oral misoprostol. In both cases, cervical ripening treatment was followed by rupturing membranes and IV oxytocin if needed. Cesarean rates overall were 23% with the catheter vs. 19% with misoprostol and 29% vs. 25% in 1st-time mothers. Chorioamnionitis rates were reported as “comparable,” and 2% of newborns had 5-min Apgar score < 7 in both groups. Time to vaginal birth was shorter in the balloon catheter group, but this may have been because women receiving misoprostol were more likely to have Bishop score 0-2, a measurement of cervical readiness for labor, than women having the catheter (42% vs. 9%) as well as being more likely to be 1st-time mothers (62% vs. 55%). Five doses of misoprostol, the average needed to prepare the cervix adequately, cost 9 euros and one balloon catheter cost 2 euros.
The Take-Away: Equivalency makes the balloon catheter the better option because unlike balloon catheters, misoprostol can cause severe adverse outcomes.
*The balloon catheter is threaded through the cervix, and the balloon is inflated with saline to hold it in place.Theory has it that the inflammatory response to the irritation promotes the ripening process. Once the cervix begins dilating, the catheter falls out, and the induction proceeds.