Abstract

Concerns have been raised as to the safety of using pivaloyl-conjugated beta-lactam antibiotics during pregnancy as they cause carnitine depletion. Restrictions have been recommended in some Scandinavian countries as drug-induced carnitine depletion could constitute a risk to the developing foetus. One of these drugs, pivmecillinam, is widely used against urinary tract infections but few data exist concerning its safety in pregnancy. In a cohort study, we compared the prevalences of congenital abnormalities, pre-term delivery, low birth weight, low Apgar score and neonatal hypoglycaemia in the offspring of 414 women who had at least 1 prescription for pivmecillinam redeemed during pregnancy with those of the offspring of 7472 pregnant women for whom no drugs were prescribed during pregnancy. The prevalence of congenital abnormalities was 1.7% among 119 infants exposed in the first trimester and 3.7% among the reference group [odds ratio (OR) 0.46; 95% confidence interval (CI) 0.11-1.86]. We found no significantly increased risks in either pre-term delivery (OR 0.91, 95% CI 0.11-1.86), low birth weight (OR 0.57, 95%, CI 0.23-1.41), low Apgar score (OR 2.32, 95% CI 0.30-18.16) or hypoglycaemia (OR 0.73, 95% CI 0.18-3.00) that were induced by carnitine depletion. No significantly increased risk in adverse birth outcome was therefore found in women treated with pivmecillinam.