Common antibiotics taken during pregnancy linked to increased risk of birth defects

Pregnant African woman

Taking some common antibiotics during the first trimester of pregnancy was linked with higher risk of birth defects, according to a new study.

The study, published Wednesday in the medical journal BMJ, found an increased risk of birth defects in the children of women who were prescribed macrolides during the first three months of pregnancy compared to mothers who were prescribed penicillin.

Macrolide antibiotics include erythromycin, clarithromycin and azithromycin, and they are used to treat infections, such as pneumonia, bronchitis and urinary, skin and sexually transmitted diseases. They are often prescribed for patients who are allergic to penicillin. According to the study, macrolides are one of the most frequently prescribed antibiotics in Western countries.

The study analyzed data from 104,605 children born in the United Kingdom between 1990 and 2016 and who were born to mothers prescribed either penicillin or macrolides. Researchers looked for birth defects and neurodevelopmental disorders diagnosed later in life.

The study found that prescribing macrolides to pregnant women during the first trimester increased the risk of major malformations to 28 of 1,000 births, compared 18 per 1,000 births with penicillin. Specifically, the risk of cardiac malformations was higher.

The study did not find a link between macrolides prescription and neurodevelopmental disorders. There was also no associated risk between birth defects and macrolides prescribed before conception.

Published: February 22, 2020