Adverse Pre-and Postnatal Events Reported to FDA in Association with Maternal Atenolol Treatment in Pregnancy
Atenolol is a beta-adrenoreceptor blocker used for treatment of hypertension in pregnancy. This study evaluates the reporting frequency of adverse pre- and postnatal outcomes in a series of 70 cases of maternal exposure during gestation, derived from 140 reports to FDA with Atenolol as a suspect drug. Pre-existing maternal hypertension was the main indication for treatment in 70% of the cases. In the majority of cases, the treatment was started before gestation and involved its entire duration; the doses ranged from 25 to 150 mg/day. Concomitant use of other antihypertensive (but not ACE inhibitors) was reported in 25% of the cases. Complications of pregnancy with spontaneous abortion, pre-term labor and oligohydramnios were uncommon. Frequently reported prenatal adverse event were intrauterine growth retardation (35% of cases) and stillbirth (21%) often secondary to placental hypoplasia. Congenital malformations, without a specific pattern, were registered in 25% of the cases, but their association to Atenolol was unclear due to lack of information about other risk factors. The most common adverse outcomes in over 60% of the cases were early postnatal complications (severe hypoglycemia and bradycardia - reversible after discontinuation of exposure, respiratory distress and hypotonia), and postnatal developmental disorders (infant growth and weight gain delays). Theses effects were more likely to to occur with longer duration of treatment and exposures during the last trimester of pregnancy. The observed events are suggestive of a role for atenolol in the pathogenesis of developmental disorders through its effect on maternal/fetal cardiovascular parameters.