Digital insertion of Foley catheter 16F versus 22F versus 28F in unripe cervix labor induction: A randomized trial.

Aim: To explore digital insertion in dorsal recumbent position of 16F, 22F, or 28F catheter bores on insertion failure, duration, and pain in unripe cervix labor induction.
Methods: A randomized trial was performed in a University hospital in Malaysia. Term women scheduled for labor induction, Bishop score ≤ 5, singleton, cephalic presentation, intact membrane, and reassuring pre-induction fetal heart rate tracing were recruited. Women with known gross fetal anomaly, allergy to latex and inability to consent or language difficulty were excluded. Participants were randomized to 16F, 22F, or 28F Foley catheter. Primary outcome was insertion failure and main secondary outcomes were insertion duration and pain (assessed by a Visual Numerical Rating Scale [VNRS] 0-10, higher score more pain). Analysis is done by analysis of variance (ANOVA), Kruskal-Wallis, and chi square test across the three arms and by t test and Mann-Whitney U test for pair wise comparisons.
Results: One hundred twenty-seven participants' data were analyzed. The insertion failure 7/43(16%) versus 4/42(10%) versus 5/42(12%), p = 0.64, insertion duration median [IQR] 2.8 [1.8-4.8] versus 2.8 [1.7-3.7] versus 2.8 [1.7-4.3] min, p = 0.68 and insertion pain VNRS mean {SD} 4.2 {2.5} versus 3.4 {2.3} versus 3.6 {2.2}, p = 0.26, insertion to delivery interval 26.0 {9.7} versus 25.6 {9.1} versus 22.8 {7.4} h, p = 0.45, and spontaneous vaginal delivery 20/43 (45%) versus 23/42(55%) versus 25/42(60%), p = 0.48 for 16F versus 22F versus 28F arms, respectively. Pairwise comparisons were not different.
Conclusion: Foley catheter 16F versus 22F versus 28F resulted in similar digital insertion performance in the dorsal recumbent position for unripe cervix labor induction.
Clinical Trial Registration: https://doi.org/10.1186/ISRCTN21224268.
(© 2022 Japan Society of Obstetrics and Gynecology.)