Witter 1987.

Study characteristics
Methods	RCT
Participants	Number of women randomised: 200 Setting: Baltimore, USA Study date: not reported Inclusion criteria GA: 42 completed weeks (enrolled at 41 weeks, intervention at 42 weeks) Uncomplicated pregnancy Exclusion criteria No additional criteria reported State of cervix: not mentioned
Interventions	Induction group (n = 103): oxytocin infusion with AROM when possible versus EM group (n = 97): Estriol measurements 2‐3/week. In both groups women initiated fetal movement counting. If reduced fetal movements, FHR and estriol testing were undertaken at 41 completed weeks.
Outcomes	Mother: GA at birth; length of hospital stay; urinary estriol/creatinine ratio; maternal complications; endometritis; pre‐eclampsia; PROM; caesarean section + indications Baby: birthweight; biparietal diameter; placental weight; Dubowitz score (assesses infant GA); SGA/AGA/LGA; fetal distress; meconium staining; infant complications; Apgar scores (< 7 at 5 minutes); fetal anomalies; post‐mature infants; meconium aspiration
Notes	Funding: not reported Declarations of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The randomisation sequence was generated using a computer‐generated random number table.
Allocation concealment (selection bias)	Unclear risk	Allocation concealment was achieved using sequentially labelled sealed envelopes, but there was no mention of opaqueness.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Appeared that blinding was not feasible
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinded outcome assessment was not mentioned.
Incomplete outcome data (attrition bias) All outcomes	Low risk	3/103 women and 2/97 women in the induction and EM groups dropped out of the study; 35/103 women and 39/97 in the induction and EM groups birthing prior to 42 completed weeks (and were included); all were included in the analyses.
Selective reporting (reporting bias)	Unclear risk	No detailed outcomes were prespecified in the methods; perinatal death was not reported. No access to trial protocol to further assess selective reporting
Other bias	Low risk	Appeared to be free of other bias

^{AGA: appropriate for gestational age;
AROM: artificial rupture of membranes/amniotomy;
CTG: cardiotocography;
EBL: estimated blood loss;
EFW: estimation of fetal weight;
EM: expectant management;
FHR: fetal heart rate;
GA: gestational age;
HIE: hypoxic ischaemic encelopathy; 
HIV: human immunodeficiency virus;
IOL: induction of labour;
IND: induction;
ITT: intention to treat;
IU: international units;
IUFD: intrauterine fetal death
IUGR: intrauterine fetal growth restriction 
IV: intravenous;
IVF: in‐vitro fertilisation;
LGA: large‐for‐gestational age;
LMP: last menstrual period
mIU: milli‐international units;
mU: milli‐units;
NICU: neonatal intensive care unit;
NST: nonstress test;
PGE2 (and PE2): prostaglandin E2;
PROM: premature rupture of membranes;
RCT: randomised controlled trial;
ROM: rupture of membranes;
SGA: small‐for‐gestational age}