Background: The optimal methods and settings for induction of labour (IOL) in terms of effectiveness, safety, and women'sexperience are still not elucidated.

Objective: To compare the effectiveness and safety of outpatient versus inpatient cervical ripening settings for IOL.

Search Strategy: MEDLINE, Embase, Emcare, CINAHL Plus, Scopus, Cochrane Library, WHO ICTRP and clinicaltrials.govfrom inception to July 2024.

Selection Criteria: Randomised controlled trials, viable singleton gestation, no language restrictions, all the published andunpublished data.

Data Collection and Analysis: An individual participant data meta-analysis.

Main Results: Eleven out of 18 (61.1%) eligible RCTs shared IPD, totalling 2593 pregnant individuals undergoing IOL (62.2% of allparticipants in the published RCTs). Among the shared RCTs, four used balloon catheters alone in both groups. Three RCTs com-pared outpatient balloon catheter with inpatient balloon catheter plus oxytocin. Another three RCTs compared outpatient ballooncatheter to inpatient vaginal dinoprostone. One RCT used Dilapan-S in both groups. No trials evaluating outpatient use of vaginalprostaglandins were identified. Vaginal birth (11 RCTs, 2584 women, 67.8% vs. 70.2%, aOR 0.95, 95% CI 0.70; 1.30), composite perina-tal outcome (9 RCTs, 2525 women, 11.1% vs. 11.7%, aOR 0.93, 95% CI 0.75; 1.16) and composite maternal (10 RCTs, 2480 women, 14.3%vs. 15.4%, aOR 0.89, 95% CI 0.65; 1.20) outcome did not differ between outpatient and inpatient groups. The outpatient group had alower risk of acidosis, more epidural analgesia, and more oxytocin. There were no perinatal deaths in either group.

Conclusions: Overall effectiveness, perinatal and maternal safety are comparable between outpatient setting cervical ripeningwith a mechanical method and inpatient with any method.

Trial Registration: PROSPERO: CRD42022313183