Hydralazine (versus unexposed)

Study	Country Study period Study design	Data source	Exposure definition	Non-exposure definition	Exposition period	Sample size (exposed/unexposed) Or (case / control)	Remarks	Risk of bias
Welt 1981	USA Not specified. randomized controlled trial	Duke university medical center, Durham, North Carolina, USA.	Pregnant women with underlying hypertensive disease randomly and blindly assigned to hydralazine group (25 mg 3 times per day).	unexposed, sick Pregnant women with underlying hypertensive disease randomly and blindly assigned to placebo group (3 times per day).	2nd and/or 3rd trimester	9 / 6	The main results were provided for non randomized group versus randomized group (whatever treatment in the group). The only reported results are those of randomized group, with distinction between treatment (provided in the text, not in the tables).
Welt 1981	USA Not specified. randomized controlled trial		Pregnant women were randomly and blindly assigned to 1 of 3 drug groups.		2nd and/or 3rd trimester	9 / 6

Study	Country Study period Study design	Data source	Case	Control	Exposition	Exposition period	Sample size (exposed/unexposed) Or (case / control)	Remarks	Risk of bias

Risk of bias: : NA; : low; : moderate; : serious; : critical; : unclear;