[Metabolic and cardiovascular effects of beta-blockers taken by the mother in newborn infants]. / Effets métaboliques et cardiovasculaires chez le nouveau-né des bêtabloquants pris par la mère.

The effects of beta-blockers administered to mothers with arterial hypertension were investigated in 38 neonates of varying gestational age and weight. During the first 48 hours of extra-uterine life, heart rate was continuously monitored and blood pressure and glycaemia were measured every 3 hours. Left ventricular function was studied by echocardiography on the first day post-partum, once again between the 5th and 10th days. Hypoglycaemia was observed in 42% of the neonates; 47% had one or several episodes of bradycardia and 2 had arterial hypotension. Most important, a significant improvement of left ventricular function was observed between the first and the 5th-10th days. This time-related change was not found in a control group. The cardiac dysfunction was more pronounced in neonates who had an episode of bradycardia, and although it is usually asymptomatic, it probably accounts for the fortunately rare cardiovascular collapses observed in some newborn babies.