[Effect of 2 beta-blockers on arterial hypertension during pregnancy. Results of a prospective study on 56 pregnant hypertensive women treated with atenolol and labetalol].

This study reports the results that were obtained in 56 cases of arterial hypertension in pregnancy solely by beta-blocking with Atenolol or Labetalol. Any pregnant woman whose arterial blood pressure rises to or exceeds 140/90 mm mercury in two successive examinations at intervals of 8 days with rest is considered to be hypertensive. As soon as treatment is started mothers' supervision is assured regularly by clinical and biological examinations and the dose of drug is adapted to each case. Fetal monitoring is ensured by ultrasound, cardiac rhythm tracings and hormone estimations. As far as the newborn is concerned, blood sugar and electrocardiogram measurements are taken to add to the normal examination at birth. Finally plasma levels of beta-blockers are estimated at birth in the mother and in the cord blood. The analysis of these results shows: for the mother: a fairly constant antihypertensive effect which is about the same for either drug in pregnancy. Further complementary injection therapy was needed, however, in 8 cases in labour. There were alterations in the method of delivery and in particular the Caesarean section rate rose to 12.5% and induction had to be carried out more frequently, triggered off by the slightest sign of fetal distress. As far as the child was concerned: 2 died in utero, the Apgar score was comparable to a control series, there was no bradycardia or broncho-spasm or teratogenic effect, mean weight at birth was significantly higher with Labetalol (3280 g +/- 555) than with Atenolol (2750 g +/- 630), the blood sugar levels at birth were in six cases lower than 1.4 mmol (0.25 g/l) but these were easily pu right by transfusion. The plasma levels of beta-blockers showed that there was a linear relationship between the maternal and fetal concentrations which confirmed that the two molecules pass through the placenta. This study confirms therefore that it is worth while using beta-blockers in cases of hypertension in pregnancy so long as careful observation is carried out, and it seems that the alpha constituent of Labetalol has advantages over the other.