Extra-amniotic balloon for preinduction cervical ripening: a randomized comparison of weighted traction versus unweighted.

OBJECTIVE

To determine whether a weighted versus unweighted balloon catheter achieved a shorter first stage of labor.

METHODS

This was a randomized trial of patients undergoing induction with Bishop score <4. Women were randomized to weighted balloon catheter with 1000 mL fluid bag or unweighted catheter taped to the thigh.

RESULTS

A total of 60 women were randomized. The time from balloon catheter insertion until discontinuation was significantly longer in the unweighted group 4.62 ± 0.65 h versus 1.59 ± 0.2 h in the weighted group (p = 0.001). This resulted in longer cervical ripening/first stage of labor in the unweighted (18.52 ± 0.96 h) versus weighted group (15.3 ± 0.99 h) (p = 0.025). The unweighted balloon catheter had a shorter first stage of labor as gravidity increased (p = 0.007) and as race went from white to non-white (p = 0.003). There was no difference in perceived pain after balloon insertion (p = 0.0942), or Bishop score after balloon discontinuation (p = 0.1661).

CONCLUSION

The total time from cervical ripening to the end of the first stage of labor is significantly shortened with the weighted balloon catheter.