Argentina 1990.

Methods	Described as a “Prospective, randomized, comparative study”.
Participants	90 women with severe chronic hypertension during pregnancy or severe pregnancy‐induced hypertension, with or without proteinuria. Severe hypertension defined as BP ≥ 160/100 mmHg. Initial readings of BP were 24 hrs apart and follow‐up was weekly. No drugs were administered during the 1st 24 hrs after hospitalisation. Women with hypertensive emergencies were excluded as well as women requiring more than 1 drug to control their BP.
Interventions	Atenolol, 50‐200 mg daily (n = 30). Ketanserin, 80‐120 mg daily (n = 30). Alpha methyldopa, 500‐2000 mg daily (n = 30).
Outcomes	BP at onset of treatment, weekly for 3 weeks, and at the end of pregnancy; adverse effects from drugs; preeclamptic clinical signs and symptoms; creatinine, haematocrit, proteinuria and uric acid levels; fetal vitality (through weekly non‐stress tests and ultrasound studies).   Perinatal outcomes: gestational age at delivery; birthweight; 1‐min Apgar score; fetal and neonatal mortality.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method not described.
Allocation concealment (selection bias)	Unclear risk	Method not described.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Different drug regimens would mean blinding women and staff was not possible.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Some blinding of outcome assessment apparent, “All the patients were hospitalized and their preeclamptic clinical signs and symptoms, as well as the adverse effects from the drugs, were weekly evaluated by residents who ignored the drug administered to the patients, and who simply elicited from them, by means of a questionnaire, if they presented or not with those symptoms.” This is not likely to be a successful method of blinding.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	It was not clear how many women were excluded after randomisation (e.g. women whose BP increased and became an emergency). It appears that full data were available for the 90 included women.
Selective reporting (reporting bias)	Low risk	All expected outcomes reported within the results.
Other bias	Low risk	Baseline characteristics similar, although 19/30 in the ketanserin group had PI hypertension compared with 13/30 in the atenolol and 9/30 in the alpha methyldopa groups.