Foley's catheter balloon for induction of mid-trimester missed abortion with or without traction applied: a randomized controlled trial

Objective: To determine whether the traction placed on a transcervical Foley catheter balloon inserted for the induction of mid-trimester missed abortion results in faster time of abortion.Study design: It was randomized clinical trial conducted at Assiut Woman's Health Hospital, Egypt, from September 2016 to August 2017 on women with missed abortion in the mid-trimester. Participants were randomly assigned to transcervical Foley catheter balloon insertion with or without traction. The primary outcome of this study was insertion to abortion time. The secondary outcomes included insertion to catheter expulsion time, vaginal bleeding, and pain associated with insertion. The outcome variables were analyzed using Mann-Whitney U and chi-square tests. A logistic regression model was utilized to examine the association between patient's characteristics and the failure of Foley catheter balloon expulsion within 24 hours.Results: Two hundred women were recruited (100 women in each group). The insertion to abortion time was significantly shorter in group I (traction group) than group II (no traction group) (16.49 ± 2.59 versus 18.24 ± 3.30 hours; p = .000). Insertion to balloon expulsion time in group I was also significantly short (7.92 ± 0.86 versus 9.12 ± 1.19 hours; p = .000). However, a significantly higher rate of vaginal bleeding and a higher degree of pain were reported by the women in group I (p = .008, p = .000; respectively). The nulliparity, longer interpregnancy interval (>22 months), smaller gestational age (<14 weeks) and lower Bishop Score before insertion (<2) were significantly associated with a higher likelihood of Foley catheter balloon expulsion failure within 24 hours.Conclusion: The small time advantage of traction does not compensate for the downsides of traction, mainly pain, analgesic use, and vaginal bleeding.