Iran 2011.

Methods	Randomised controlled trial. Women’s Hospital, Tehran, Iran.
Participants	50 pregnant women admitted for labour diagnosed with severe PE or chronic hypertension superimposed by PE, of at least 24 weeks' gestation.  Hypertensive emergency was defined as measured sustained SBP ≥ 170 mmHg or DBP ≥ 105 mmHg. Exclusion criteria: women diagnosed with heart disease or severe renal impairment or cerebrovascular accident.
Interventions	Oral nifedipine 10 mg capsules, administered initially at a dose of 10 mg, then 20 mg, with intervals of 20 min up to a maximum of 5 doses or when desired BP (150/90‐100) achieved (n = 25). IV hydralazine 5 mg, administered initially at 5 mg and repeated in 10 mg doses, up to maximum of 5 injections in intervals of 20 min.  IV hydration were all set at rate of 125 mg/h (n = 25).
Outcomes	Primary: time and frequency of doses to achieve target BP. Secondary: urinary output; maternal (headache; hypotension; flushing; nausea) and neonatal side‐effects (fetal heart rate abnormalities; neonatal Apgar score).
Notes	All women received prophylactic infusion of MgSO4 continually to avoid convulsion.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Referred to a random number table “We dispensed either nifedipine or hydralazine according to a random number table”.
Allocation concealment (selection bias)	Unclear risk	Not described.
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding, “It was not possible for us to blind the study, because there was no placebo group due to ethical considerations”.
Blinding of outcome assessment (detection bias) All outcomes	High risk	No blinding, “It was not possible for us to blind the study, because there was no placebo group due to ethical considerations.”.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No mention of loss to follow‐up.
Selective reporting (reporting bias)	Low risk	All expected outcomes fully reported upon.
Other bias	Low risk	None apparent.  Baseline characteristics of 2 groups similar.