Doany 1997.

Methods	Random number tables, allocation concealment unclear. Factorial design ‐ 4 groups.
Participants	In total 150 women undergoing induction of labour 4 groups only 2 arms of trial (65 women) eligible for inclusion in this review (vaginal PGE2 gel vs placebo). Inclusion criteria: singleton pregnancy, cephalic presentation, reactive NST, AFI between 5 and 25, fetal weight between 2500 g and 4500 g, uterine contractions less frequent than 5 minutes. Exclusion criteria: no prenatal care, previous uterine surgery, acute or chronic medical or psychiatric illness or drug use.
Interventions	2 mg PGE2 vaginal gel (n = 37) or identical placebo gel (n = 28). Reassessed 7 days afterwards, then every 2‐4 days after that to a maximum of 307 days. (Outpatient administration.)
Outcomes	Number of fetal surveillance visits, onset of spontaneous labour, incidence of SROM, use of oxytocin, admission to delivery time, total length of labour, mode of delivery, meconium‐stained liquor, 5‐minute Apgar scores, PPH, and amnionitis.
Notes	Only 2 arms of trial analysed here (groups I and II). Additional 2 arms with membrane stripping +/‐ vaginal prostaglandins (groups III and IV) included in review focusing on membrane stripping. UCLA Medical centre, University of California, USA.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number tables.
Allocation concealment (selection bias)	Unclear risk	Method of concealment unclear.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"Double blind" placebo control.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	"Double blind" placebo control.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No patients lost to follow‐up.
Selective reporting (reporting bias)	Unclear risk	Unclear which outcomes prespecified.
Other bias	Unclear risk	Small single centre RCT.