The study has found that pregnant women taking macrolide antibiotics have a high risk of having a child with birth effects. Researchers found that pregnant women taking macrolides had a slightly greater risk of having a child with a major malformation, by using data on above 100,000 children.
Researchers from the UCL Great Ormond Street Institute of Child Health examined data on 104,605 children who were born during 1990to 2016, whose mothers were given macrolides or penicillin at some point of their pregnancy from the fourth gestational week until the childbirth.
The researcher used two control groups, with one consisting of 53,735 children who were the siblings of the children in the study group, and a further 82,314 whose mothers have prescribed the antibiotic drugs before they conceive. They followed up with the children after about 5.8 years after their birth.
Findings of the study are published in the BMJ.
Macrolides are one of that class of antibiotics that are most commonly prescribed to the pregnant ladies in the Western countries. It includes roxithromycin, erythromycin, clarithromycin and azithromycin. Advice on the use of such antibiotics of pregnant women varies.
Major birth defects were noted in 21.55 per 1,000 children, whose mothers were taking macrolides, and 17.36 per 1,000 children whose mothers were taking penicillins during pregnancy.
Among those who took macrolides in their first trimester, 27.7 per 1,000 births had major birth defects, as compared to 19.5 per 1,000 who took macrolides in their second or third trimester. There was no such significant difference in the malformation rates between trimesters in ladies who took penicillin.
Using macrolide antibiotics during pregnancy was related to an elevated risk of a baby born with malformed genitals. Using erythromycin specifically during the first trimester was linked with a greater risk of any kind of defect.
No significant link was observed between drug usage and neurodevelopmental disorders like epilepsy, cerebral palsy, autism, deficit hyperactivity disorders.
The researchers concluded that the study outcomes revealed that macrolides must be used with care during pregnancy and if possible then alternative antibiotics should be given until further information is available.
The research follows the recent study in which existing evidence on macrolides was keenly reviewed. In which scientists observed an increased risk of miscarriage because of drug usage, but found less consistent evidence which links to birth defects, epilepsy and palsy. However, the methods used by the researchers could not prove that these drugs were the actual cause of birth defects.
The lead author, Heng Fan said that if any causal link could be shown then the study outcomes suggest that an additional four newborn babies would be having cardiovascular disorders for every 1,000 children exposed to macrolides instead of penicillins during the first trimester.
Co-author Ruth Gilbert said that these findings suggest to avoid macrolides during pregnancy and to use alternative antibiotics if feasible.
Experts urged pregnant women not to be much worried by these findings.
The professor of pharmacoepidemiology, Stephen Evans at the London School of Hygiene and Tropical Medicine said that the study was well –conducted and the results are also well-analyzed. He added that findings of the paper should be directed at the prescriber rather than at the patients.