Outpatient balloon catheter versus expectant management for post-term labor induction in nulliparous women: A randomized trial.

Background: Increased use of labor induction has renewed interest in outpatient cervical ripening. Post-term pregnancy (i.e., ≥41 weeks) is a specific situation of increased neonatal risk, including greater risk of perinatal death and adverse perinatal outcomes. While a high proportion of these patients will need induction, outpatient management of this specific population has never been studied. Therefore, our objective was to compare two policies of management of post term pregnancies: the use of a transcervical Foley catheter for outpatient cervical ripening compared with expectant management.

Methods: Multicenter, randomized controlled open-label study comparing home induction with a Foley catheter versus expectant management. Inclusion criteria were nulliparous, live singleton fetus in a vertex position, post-term (at 41 + 4 days), requiring cervical ripening (Bishop score <6), intact membranes, and distance home-hospital within 40 min. The primary endpoint was change in Bishop score beetween randomization (41 + 4 days) and consultation (41 + 5 days).

Results: Forty-five women were included: 21 in the home induction group and 24 in the control group. The study was stopped due to low recruitment. The difference in Bishop score increases one day after randomization approached significance (p = 0.055), with home induction showing a larger change compared with expectant management (Cohen's d = 0.60; 95 % confidence interval [CI] -0.002 to 1.21). Regarding change in Bishop score, 81 % of home induction group patients had a better score at 41 + 5 days versus 52.2 % in the control group (relative risk = 1.55; 95 %CI 0.99 to 2.15).

Conclusion: By specifically evaluating home induction in nulliparous women with post term pregnancies, we observed a Bishop score improvement in the home induction group. These data support further evaluation of induction methods and birth experiences in a larger cohort of this population.

Trial Registration: The study was registered under European policy (number EudraCT 2015-A01298-41) and on www.clinitrials.gov (number NCT02932319). Date of registration: 13/10/2016, Date of initial participant enrollment: 31/03/2017.