Hydralazine was the most common drug for others to be evaluated against .
Diazoxide , given as 75 mg bolus injections , appears to be associated with maternal hypotension requiring treatment , and ketanserin is less effective than hydralazine at reducing blood pressure .
There is no other clear evidence that any one of the other antihypertensive agents is better than another for women with severe hypertension during pregnancy .
Exceptions are diazoxide and ketanserin , which are probably not good choices
BACKGROUND Very high blood pressure during pregnancy poses a serious threat to women and their babies .
The use of drugs to lower blood pressure will reduce this risk for the women , and possibly also for the baby .
OBJECTIVES The objective of this review was to compare different antihypertensive drugs used for treatment of severe hypertension during pregnancy .
Maternal and fetal haemodynamics in hypertensive pregnancies during maternal treatment with intravenous hydralazine or labetalol
Summary . Intravenous treatment with 10 mg of hydralazine or 100 mg of labetalol was r and omly allocated to 30 hypertensive pregnant women .  Umbilical artery flow velocity waveforms were recorded using a pulsed Doppler duplex scanner ( ATL Mk V ) and umbilical artery pulsatility index ( PI ) and fetal heart rate ( FHR ) were derived from these recordings . Maternal blood pressure decreased significantly after both drugs . Maternal pulse rate increased after hydralazine but did not change significantly after labetalol . FHR did not change significantly after hydralazine but decreased after labetalol . PI decreased after hydralazine and increased after labetalol‐most fetuses showed little change but a few in each group showed large changes in PI , as did two of five additional patients studied . We attributed the decrease in PI in some fetuses after hydralazine to vasodilation , and the increase in PI in some fetuses after labetalol to vasoconstriction in the fetoplacental circulation , suggesting that fetal beta‐blockade may occur after maternal treatment with labetalol
Hydralazine was the most common drug for others to be evaluated against .
Diazoxide , given as 75 mg bolus injections , appears to be associated with maternal hypotension requiring treatment , and ketanserin is less effective than hydralazine at reducing blood pressure .
There is no other clear evidence that any one of the other antihypertensive agents is better than another for women with severe hypertension during pregnancy .
Exceptions are diazoxide and ketanserin , which are probably not good choices
BACKGROUND Very high blood pressure during pregnancy poses a serious threat to women and their babies .
The use of drugs to lower blood pressure will reduce this risk for the women , and possibly also for the baby .
OBJECTIVES The objective of this review was to compare different antihypertensive drugs used for treatment of severe hypertension during pregnancy .