UK 1983b.

Methods	Allocation concealment: not stated. Authors state: "allocated at random". Stratified by gestational age. Two arms
Participants	100 women with singleton pregnancy and DBP >/= 95 mmHg x 2 at least 24 hrs apart, or > 105 mmHg x 1. Excluded: asthma, heart failure, or heart block, diabetes, renal disease, or taking other hypertensive medication.
Interventions	Exp: oral oxprenolol 80 mg x 2/day to 320 mg x 2/day. (50 women) Control: oral methyldopa 250 mg x 3/day to 1000 mg x 3/day. (50 women) If BP not controlled, hydralazine added to both groups.
Outcomes	Women: severe HT, proteinuria (> trace on dipstick), induction of labour, caesarean section, additional antihypertensive, hospital admission. Babies: perinatal death, birthweight (mean), 5‐min Apgar < 7, antenatal fetal heart rate.
Notes	Korotkoff phase IV used for DBP. Random zero sphygmomanometer. Funding: funded by industry.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described.
Allocation concealment (selection bias)	Unclear risk	Not described "...allocated at random...". Stratified by gestational age.
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	4 women (4%) excluded, 2 lost to follow‐up, 2 abortions.
Selective reporting (reporting bias)	Unclear risk	Assessment from published study report.
Other bias	High risk	Funding: funded by industry.