Sweden 1984.

Methods	Allocation concealment: telephone randomisation, no further details. Two arms
Participants	52 women in antenatal clinic at < 37 weeks' gestation with singleton pregnancy, BP >/= 140/90 mmHg or an increase of at least 30 mmHg SBP or 15 mmHg DBP x 2 within 24 hrs. Excluded: imminent eclampsia, serious fetal distress, severe HT (> 170/110 mmHg), Rh disease, diabetes, contraindication to beta blockers, 'social or psychological handicaps'.
Interventions	Exp: oral metoprolol 100 mg x 2/day to 200 mg x 2/day. (26 women) Control: oral identical placebo x 2/day.(26 women)
Outcomes	Women: proteinuria (>/= 2+), severe HT, changed drugs due to side‐effects, hospital admission, placental abruption, caesarean section. Babies: perinatal death, gestation at delivery (mean) Apgar (mean).
Notes	Korotkoff phase V used for DBP. Additional data provided by authors. Funding: funded by charity or foundation. Declaration of interests not described.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described.
Allocation concealment (selection bias)	Low risk	Telephone randomisation (personal communication).
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind. Placebos of identical appearance.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Yes.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No.
Selective reporting (reporting bias)	Low risk	Unpublished data provided by author.
Other bias	Unclear risk	Declaration of interests not described. Funded by charity or foundation.