1. Gestational age, at baseline and at induction.
| Study | At baseline/enrolment (all participants) |
At induction (intervention group participants only) Mean [SD] unless otherwise indicated |
| Augensen 1987 | 41 weeks (290‐297 days) | 294.8 days (category: ≥ 41 weeks) |
| Baev 2017 | 40+6 weeks (283‐289 days) | 285.35 [0.93] days (category: 40‐41 weeks) |
| Bergsjo 1989 | 42 weeks+ (294+ days) | 294+ days, mean NR (category: ≥ 41 weeks) |
| Brane 2014 | between 37+0 and 41+6 weeks | 282 [5.9] days (category: 40‐41 weeks) |
| Breart 1982 | 37 to 39 weeks (259‐273 days) | 259‐273 days, mean NR (category: < 40 weeks) |
| Chakravarti 2000 | < 41 weeks (< 290 days) | < 290 days, mean NR (category: 40‐41 weeks) |
| Chanrachkul 2003 | 41+3 weeks (290 days) | 290.4 [1.4] days (category: ≥ 41 weeks) |
| Cohn 1992 | 42+0 weeks (294 days) | 294+ days (category: ≥ 41 weeks) |
| Cole 1975 | 39 to 40 weeks (273‐280 days) | 273‐280 days, mean NR (category: < 40 weeks) |
| Dyson 1987 | 41 weeks+ (287 days+) | 296.3 [2.6] days (category: ≥ 41 weeks) |
| Egarter 1989 | 40 weeks (280 days) | 280 days (category: 40 to 41 weeks ) |
| Gelisen 2005 | 41 weeks+ 0‐1 | 286‐288 days (category: ≥ 41 weeks) |
| Grobman 2018 | 380 weeks to 386 (268‐274 days) | 390 weeks to 394 weeks (273‐279 days) (category: < 40 weeks) |
| Hannah 1992 | 41 weeks+ (287 days+) | 287 days+ mean NR (authors stated that women were induced within 4 days of enrolment, and that 88% of women were 41 weeks GA, (287‐293 days GA), no further details) (category: ≥ 41 weeks) |
| Heimstad 2007 | 406 weeks (286 days) | Mean 289 [0.7] days (category: ≥ 41 weeks) |
| Henry 1969 | 41 weeks+ (287 days+) | 287+ days, mean NR (category: ≥ 41 weeks) |
| Herabutya 1992 | 42 weeks+ (294 days+) | 294+ days, mean NR (category: ≥ 41 weeks) |
| James 2001 | 41 weeks (287 days) | 287+ days, mean NR (category: ≥ 41 weeks) |
| Keulen 2019 | 405 to 410 weeks (285‐287 days) | 287 to 288 days, mean NR (category: ≥ 41 weeks) |
| Martin 1978 | 371 to 376 weeks (260‐266 days) | 273 days (category: < 40 weeks) |
| Martin 1989 | 41 weeks (287 days) | 287+ days, mean NR (category: ≥ 41 weeks) |
| Miller 2015 | 380 to 386 (266 to 272 days) | 390 to 396 weeks (273‐279 days), mean NR (category: < 40 weeks) |
| NICHHD 1994 | 41 weeks+ (at least 287 days) | 287 days to < 301 days, mean NR (category: ≥ 41 weeks) |
| Nielsen 2005 | 390 to 396 weeks (273‐279 days) | Within a week after enrolment, therefore between 39 and 40 weeks (274 to 280 days) (mean time between enrolment and induction of labour 3.7 days) (category: < 40 weeks) |
| Ocon 1997 | Unclear (due to incomplete translation of paper) | 42 completed weeks (category: ≥ 41 weeks) |
| Roach 1997 | 410 to 416 weeks (287 to 293 days) | 42 completed weeks (category: ≥ 41 weeks) |
| Sahraoui 2005 | 410 to 416 weeks (287‐293 days) | 287‐293 days, mean NR (category: ≥ 41 weeks) |
| Sande 1983 | 400 and 406 weeks | 280 to 286 days (category: 40 to 41 weeks) |
| Sargunam 2019 | ≥ 39 weeks (≥ 273 days) | ≥ 273 days (category: < 40 weeks) |
| Suikkari 1983 | 10 days or more post‐date | 287+ days (category: ≥ 41 weeks) |
| Tylleskar 1979 | At least 37 weeks (259+ days) | 40 weeks, EDD +/‐ 2 days (category: 40 to 41 weeks) |
| Walker 2016 | 360 to 396 weeks (252‐279 days) | 390 to 396 weeks (273‐279 days) (category: < 40 weeks) |
| Wennerholm 2019 | 406 to 411 weeks (286 to 288 days) | 288.7 [1.1] weeks (category: ≥ 41 weeks) |
| Witter 1987 | 41 weeks (293 to 298 days) | 42 weeks (293‐298 days) (category: ≥ 41 weeks) |
EDD: estimated due date GA: gestational age NR: not reported SD: standard deviation