Abstract
Blood pressure control in preeclampsia is inevitable for both maternal and fetal wellbeing. The uteroplacental insufficiency is considered as one of the causes of preeclampsia and intrauterine growth retardation (IUGR), so that we have to keep in mind not to decrease uteroplacental blood flow when using anti-hypertensive drugs.
For hypertensive pregnant women, hydralazine and alphamethyldopa have widely been used. Alpha-blockades, beta-blockades or Ca++-antagonists have recently been used as antihypertensive drugs in preelampsia. In the same manner, labetalol hydrochloride which is alpha- and beta-blockade, has become the first choice for the same purpose, for it reduces peripheral blood vessel resistance without decreasing cardiac output which may improve uteroplacental insufficiency.
From 1985 to 1987 we investigated the effects of labetalol on maternal blood pressure and on babies' condition, by giving it to 9 pregnant women who became severe preeclampsia on the 2nd to the 3rd trimester. Labetalol was started by 150mg/day or 200mg/day orally and doubled every 3 or 4 days, until systolic blood pressure was controlled between 130 to 160mmHg and diastolic blood pressure between 90 to 110mmHg. Six out of the nine cases required labetalol of more than 600mg/day, in one case the maximum dose was 1000mg/day.
The mean gestosis index was 4.11 on admission, and decreased significantly to 3.44 after the drug administration. Proteinuria and edema also improved. All the babies were alive, five of which were small for dates (SFD). No adverse effects were recognized in both mother and newborn, except for 2 babies who developed transient tachypnea.
We conclude that labetalol hydrochloride can be the first choice of the drug in controlling blood pressure of preeclamptic patients without side effects.
