According to the study, children of mothers who were prescribed macrolides – a class of drugs used to treat common bacterial infections – in the first trimester of pregnancy are at an increased risk of major birth defects when compared with penicillin. The authors, including HDR UK researcher Professor Ruth Gilbert, concluded that the drugs should be used ‘with caution.’ Professor Gilbert says “this study shows a low risk of birth defects associated with macrolide antibiotics, so it would be better to use alternative antibiotics during pregnancy for women with a bacterial infection. Untreated infection is damaging to the unborn baby, so women should not avoid antibiotics when they are needed.”
Researchers analysed data from 104,605 children born in the UK from 1990 to 2016 using a large UK primary care research database – the Clinical Practice Research Datalink (CPRD). The size and quality of this database makes it possible to examine prescribing in pregnancy on rare outcomes such as birth defects in their children.
The research was funded by Child Health Research CIO Trust, China Scholarship Council, National Institute for Health Research and supported by Health Data Research UK.