Keulen 2019.

Study characteristics
Methods	Multicentre RCT (non‐inferiority trial)
Participants	Number of women randomised: 1815 randomised Setting: 123 primary care midwifery practices and 45 hospitals (secondary care) equally distributed across the Netherlands Study date: study conducted 2012‐16 Inclusion criteria: Low‐risk, uncomplicated singleton pregnancy Fetus in stable cephalic position Certain GA of 405 to 410 weeks with no contraindications to EM until 42 weeks Just over half the women were nulliparous Exclusion criteria: Age < 18 years ROM, or in labour, or both Non‐reassuring fetal status (e.g. no fetal movements, abnormal fetal heart rate and/or expected IUGR) Known fetal anomalies (including abnormal karyotype) that could influence perinatal outcome Contraindications to induction (including previous caesarean) Contraindications to EM (e.g. pregnancy‐induced hypertension) State of cervix: mixed ‐ in both groups three‐quarters of the women had a Bishop score < 6 at study entry
Interventions	Induction group (n = 907): Women were scheduled for induction at 410 weeks to 411 weeks. All women were primed or induced, or both according to local protocols. Women with a Bishop score < 6 received cervical priming with PGE1 (misoprostol, oral or vaginal), PGE2 (dinoprostone), Foley catheter or double balloon catheter, or a combination of these until AROM could be performed. AROM was followed by IV oxytocin if required. versus EM group (n = 908): women awaited spontaneous onset of labour until 420 weeks in their initial care setting (primary or secondary), with monitoring according to local protocol. which typically involved a combination of CTG, and sonographic assessment of amniotic fluid in secondary care at 41‐42 weeks. Women with ongoing pregnancies were scheduled for induction at 420 weeks in secondary care, following a similar induction protocol to the intervention group.
Outcomes	Mother: caesarean section; operative vaginal birth; analgesia used (reports on pain treatment during labour, and specifically on remifentanil, pethidine/promethazine/other opiates, epidural anaesthesia, other); perineal trauma (episiotomy (without tear), obstetrica anal sphincter injuries, third‐degree tear, fourth‐degree tear, episiotomy and third‐degree tear, episiotomy and fourth‐degree tear); postpartum haemorrhage (≥ 1000 mL); Baby: perinatal death; stillbirth; neonatal death; NICU admission; meconium aspiration syndrome; Apgar score < 7 at 5 minutes; birthweight
Notes	Funding: grant from the Netherlands Organisation for Health Research and Development ZonMw (grant No 171202008) Declarations of interest: "BWM is supported by a National Health and Medical Research Council practitioner fellowship (GNT1082548) and reports consultancy for ObsEva, Merck, and Guerbet; no support from any other organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years, no other relationships or activities that could appear to have influenced the submitted work."
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Web‐based program (ALEA) using randomly permuted block sizes of 4 and 2, stratified by centre
Allocation concealment (selection bias)	Low risk	Central (web‐based) randomisation
Blinding of participants and personnel (performance bias) All outcomes	High risk	Women and staff were aware of assignments.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	‘"he statistician who performed the analyses was blinded to the allocation of the participants and performed the analysis according to a predefined analysis plan."
Incomplete outcome data (attrition bias) All outcomes	Low risk	900/907 women allocated to induction were analysed in ITT analyses (7 were excluded – 1 withdrew consent, and 6 were not eligible); 901/908 women allocated to EM were analysed in ITT analyses (7 were excluded due to ineligibility).
Selective reporting (reporting bias)	Low risk	Wide range of outcomes reported, as specified in published protocol.
Other bias	Unclear risk	"Since in our trial all women in the 41 week induction group received obstetrician led intrapartum secondary care whereas in the expectant management group until 42 weeks 68.7% of the women received midwifery led primary care at start of labour and 34.3% at time of birth, it could be suggested that our study is prone to performance bias (different care) and measurement bias (different assessment of neonates)."