South Africa 1998.

Methods	Please see details below.
Participants	822 women with severe PE: at least 2 of DBP >/= 110 mmHg, significant proteinuria, symptoms of imminent eclampsia. Also, > 16 years, no previous anticonvulsant.
Interventions	MgSO4: 4 g IV in 200 ml saline over 20 min, then 1 g/hr (200 ml over 4 hr) until 24 hr after delivery. Placebo: 200 ml over 20 min, then 200 ml over 4 hours until 24 hr after delivery. Treatment stopped if urine output < 30 ml/hr. Serum monitoring not required. Women transferred from outlying clinics received 1 g clonazepam IV before transfer. Women not transferred were given 1 g clonazepam IV after randomisation.
Outcomes	Woman: death, eclampsia, toxicity, antihypertensive therapy, caesarean section. Child: stillbirths.
Notes	All women given clonazepam 1 mg. Recruitment over 13 years, 1982‐95.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Not described.
Allocation concealment?	High risk	Allocation by sealed opaque envelopes containing card marked solution A or B. Cards, but not envelopes, consecutively numbered. Envelopes distributed in batches of 20, with equal numbers of A and B. Solutions prepared by pharmacy, and identity of A and B changed periodically.
Blinding? All outcomes	Low risk	Investigators blinded to identity of solutions.
Incomplete outcome data addressed? All outcomes	Low risk	123 excluded as envelopes and data sheets lost. Review of hospital records suggests no eclampsia amongst these women. Further 14 post randomisation exclusions (4 delivered before treatment, 3 no solution available, 4 MgSO4 before entry, 2 no consent, 1 anuric). None had eclampsia.