France 1987.

Methods	Allocation concealment: quote "blinded envelopes". Stratified in blocks of 10 at each clinic. Multicentre, 12 hospitals. Withdrawals: 12 women (6%). 5 labetalol (3 lost to follow‐up and 2 given methyldopa) and 7 methyldopa (all lost to follow‐up). Two arms
Participants	188 women with singleton pregnancy at 12 to 34 weeks' gestation, booked < 20 weeks and DBP >/= 90 mmHg. Excluded: previous antihypertensive treatment this pregnancy, diabetes, depression, contraindication to beta blockers.
Interventions	Exp: oral labetalol 200 mg x 2/day to 600 mg x 2/day. (96 women) Control: oral methyldopa 250 mg x 2/day to 750 mg x 2/day. (92 women)
Outcomes	Women: proteinuria (> 2+ or 0.5 g/L), admission to hospital, caesarean section, elective delivery, additional antihypertensive, side‐effects, changed drugs due to side‐effects. Babies: stillbirth, neonatal death, admission to SCBU, SGA (< 5th centile, excludes stillbirths), preterm delivery (< 37 weeks), 5 mins Apgar < 8.
Notes	Korotkoff phase IV used for DBP. Funding: funded by industry.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "...stratified blocks of ten at each clinic..."
Allocation concealment (selection bias)	Low risk	Blinded envelopes.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open‐label trial.
Blinding of outcome assessment (detection bias) All outcomes	High risk	No.
Incomplete outcome data (attrition bias) All outcomes	Low risk	12 women (6.4%) excluded from analysis: 10 lost to follow‐up (3 from labetalol and 7 from methyldopa group), and 2 quote: "protocol violation".
Selective reporting (reporting bias)	Unclear risk	Assessment from published study report.
Other bias	High risk	Groups appear comparable at baseline. Funded by industry.