Sawai 1991.

Methods	Randomised by drawing of envelopes.
Participants	50 women requiring induction of labour. Inclusion criteria: unfavourable cervix (BS < 9). Exclusion criteria: diabetes, hypertension, previous uterine surgery, abnormal FHR tracings, vaginal bleeding, SROM, regular uterine contractions, non‐vertex presentation, macrosomia, IUGR, oligohydramnios or multiple gestations.
Interventions	2 mg PGE2 vaginal gel (n = 24) or identical placebo (n = 26). Instillation following assignment of BS, repeat treatments and assessments twice weekly (outpatient administration). Induction with oxytocin at 44 weeks if needed.
Outcomes	Number of gel applications, change in BS, mode of delivery, oxytocin use, hyperstimulation, meconium staining, Apgar scores, cord pH, NICU admission.
Notes	University of South Florida College of Medicine, USA.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomised by drawing of envelopes", method of random sequence generation not reported.
Allocation concealment (selection bias)	Unclear risk	"Randomised by drawing of envelopes", Method of allocation concealment not reported.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No blinding but "identical placebo used".
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No blinding.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No randomised patients lost to follow‐up.
Selective reporting (reporting bias)	Unclear risk	Unclear which outcomes prespecified.
Other bias	Unclear risk	Small, single centre RCT, source of funding not clear.