[Neonatal outcome after exposure to beta adrenergic blockers late in pregnancy]

To analyse neonatal effects after in utero betablockers exposure and the pertinence of recommendations delivered by our team.

We report 44 pregnancies exposed to betablockers during the late pregnancy including the period of delivery about which the Regional Pharmacovigilance Center of Tours (CRPV) was questionned.

Among the 39 children for whom we know the follow up, 22 had neonatal adverse effects of which 19 could be explained by in utero exposure to betablockers i.e. an hypoglycaemia (11 times), a bradycardia (six times), a bradycardia and hypoglycemia (one time) and an hypotension (one time). A drug-related effect was retained for eleven newborns (27%) and another etiology could be evoked in the eight others. The risk of neonatal adverse effects seems to increase in newborns exposed to labetalol (5/11), to betaxolol (1/2) or to propranolol (2/6) or when the dose is high. The eight newborns who had intrauterine growth retardation were generally more often exposed to atenolol than eutrophic newborns. Four babies had malformations.

Our recommendation was an hospitalization 44 times (100%) to monitor heart rate, blood pressure and glycemia. When the follow-up is known, hospitalization was performed in 88% of the cases. Glycemia, heart rate and blood pressure were monitored in all the hospitalized children and in three of the five not hospitalized children. Our recommendation seems particularly justified with regard to hypoglycemia which is often asymptomatic but whose consequences can be severe. Atenolol often provider of intrauterine growth retardation and labetalol more often at the origin of neonatal adverse effects are probably to avoid during pregnancy.