Uterine and fetal hemodynamics and fetal cardiac function after atenolol and pindolol infusion. A randomized study

To evaluate the short-term effects of intravenously given atenolol and pindolol on utero- and umbilicoplacental vascular impedance, fetal hemodynamics and cardiac function in patients suffering from pregnancy-induced hypertension.

A total of 24 women were randomized to receive atenolol or pindolol infusion. By using pulsed color Doppler techniques, uterine, placental arcuate, umbilical fetal middle cerebral and renal arteries were examined before, at the end and 30 min after the end of infusion. Pulsatility indices (PI) were calculated to assess vascular impedance. Fetal myocardial function was evaluated by using pulsed Doppler and M-mode echocardiography. Peak systolic velocities from the ascending aorta and pulmonary trunk, and also inner diameters and fractional shortenings of both ventricles were measured.

Both drugs significantly decreased maternal blood pressure. Immediately after the infusion, maternal heart rate was significantly decreased in both groups; but the decrease was clearer and lasted longer in the atenolol group. Pindolol caused no changes in utero- or umbilicoplacental vascular impedance, while atenolol increased it in the nonplacental uterine artery. After atenolol infusion, PI in the umbilical artery was higher than after pindolol. Pindolol had no effects on fetal hemodynamics, while atenolol decreased PI value in the fetal renal artery. Peak systolic velocity in the pulmonary trunk was decreased after atenolol. Pindolol did not affect the fetal cardiac function. In subgroups with originally increased utero- or umbilicoplacental vascular impedance, the responses in uterine and umbilical vascular impedance and in fetal hemodynamics and cardiac function after atenolol and pindolol were different compared to whole groups.

Differently acting antihypertensive agents seem to affect differently uteroplacental vascular impedance. Atenolol may have some direct effects on fetal hemodynamics and cardiac function. According to our results, pindolol seems to be more preferable in the treatment of pregnancy-induced hypertension than atenolol.