Certain Antibiotics during Early Pregnancy Could Increase the Risk of Birth Defects in Children

“It's really important to take antibiotics because infection itself can be really damaging to the unborn baby.”


A new study published in the medical journal BMJ has found that women who take certain antibiotics during the first trimester of pregnancy are more likely to have children with birth defects.

Researchers found a potential risk of birth defects in children of women who were recommended macrolide antibiotics during the first three months of pregnancy than women who were advised penicillin.

Macrolides include antibiotics such as erythromycin, azithromycin, and clarithromycin, which are used to treat bacterial infections, such as bronchitis, pneumonia, urinary tract infection, bacterial skin infections, and sexually transmitted diseases. These types of antibiotics are often advised to patients who are hypersensitive to penicillin.

Macrolides are the most frequently prescribed antibiotics in Western countries, according to the study.

The researchers looked at data from more than 104,600 children born in the United Kingdom from 1990 to 2016. The children were born to mothers who have advised either macrolides or penicillin. They looked at all the children for any birth defects or neurodevelopmental disorders that were diagnosed later in life.

The authors found that prescribing macrolides to women during the first trimester of pregnancy increased the risk of major birth malformations in children, especially cardiac malformations. However, the study did not find an association between macrolides and neurodevelopmental disorders.

Study author Prof. Ruth Gilbert from University College London said. “This is a small but still significant increase and based on these findings, pregnant women and their doctors should find an alternative depending on the type of infection.”

Prof. Gilbert also cautioned about the potential risks associated with not taking antibiotics at all.

“If you’ve got a bacterial infection, it’s really important to take antibiotics because infection itself can be really damaging to the unborn baby,” said Prof. Gilbert.

In 2005, Sweden researchers warned that the use of erythromycin during the first trimester of pregnancy has been linked to heart defects in children.

One study published in the Canadian Medical Association Journal found that some common antibiotics, including macrolides, have been associated with an increased risk of miscarriage when prescribed during early pregnancy. The new study authors said, “Currently, regulatory authorities in the United States and the UK only warn against the use of azithromycin and clarithromycin for adults with a high risk of cardiovascular complications.”