Hydralazine (versus unexposed)

Study	Country Study period	Population source	Exposure definition	Non-exposure definition	Sample size	Rmk
Welt, 1981	USA Not specified.	Pregnant women with underlying hypertensive disease elected to join a protocol of intensified prenatal care and prophylactic drug therapy.	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).	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).

Study	Country Study period	Case	Control	Sample size	Rmk