Misoprostol as Oral Solution or Oral Tablet for Induction of Labour (MISOBEST): A Randomised Controlled Non‐Inferiority Trial.

ABSTRACT Objective Design Setting Population Methods Main Outcome Measures Results Conclusions Trial Registration To assess if off‐label oral solution of misoprostol compared with licensed oral tablet of misoprostol approved for induction of labour (IOL) is as efficient in resulting in vaginal delivery within 24 h, using a non‐inferiority design.Prospective, randomised, non‐inferiority, open‐label, blinded endpoint trial.Two tertiary level hospitals, Stockholm, Sweden, January 2022 to May 2023.In all, 874 women, without previous caesarean section, with an unripe cervix and a singleton, cephalic foetus at 37 + 0 to 42 + 0 gestational weeks, with a normal cardiotocography, planned for IOL were included.Women were randomised 1:1 to intervention (25 μg oral solution of misoprostol) or control (25 μg oral tablet of misoprostol) two‐hourly for a maximum of eight doses. Subsequent methods of induction followed clinical practice.The primary outcome was vaginal delivery within 24 h tested using non‐inferiority testing procedures at a non‐inferiority margin of 5 percentage points. Secondary efficacy outcomes were tested for superiority of either treatment. Analyses were by intention‐to‐treat.There were 207 (47.4%) vaginal deliveries within 24 h for women receiving oral solution and 192 (43.9%) vaginal deliveries within 24 h for women receiving oral tablet, establishing non‐inferiority with an absolute risk difference of 3.4% (95% CI −3.2% to 10.0%). Women receiving oral solution required fewer doses to reach active labour than women receiving oral tablet (5.7 vs. 6.1, p = 0.007). There were no significant differences for other secondary or safety outcomes.Off‐label oral solution of misoprostol was non‐inferior to the licensed oral tablet regarding efficacy of IOL defined as vaginal delivery within 24 h.Clinicaltrials.gov identifier: NCT05424445 [ABSTRACT FROM AUTHOR]