A recent meta-analysis of studies found that taking antibiotics in the months or weeks before pregnancy increases the risk of infertility, miscarriage, and birth defects.
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Specifically, the researchers found these risks to be linked with classes of antibiotics known as microlides and sulfonamides, and the antibiotic trimethoprim. But just how concerned should you be if you’re trying to get pregnant?
“I am more concerned about women reading [about] this and being scared to use necessary antibiotics,” says Veronica Vernon, PharmD, chair and associate professor of pharmacy practice at Butler University of College of Pharmacy in Indianapolis. “There are very real and significant health risks if someone does not treat a bacterial infection.”
She also points out that some of the studies analyzed didn’t examine why the participants were taking antibiotics or what other fertility concerns they may have had before taking them. ”If individuals were being treated for sexually transmitted infections (STIs), it is more likely that the STIs led to fertility concerns and not antibiotic use,” she says.
Still, other research suggests that antibiotic use may disrupt the vaginal microbiome, creating a potential impact on fertility.
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The vaginal microbiome is composed of the “normal” microorganisms that live in the female genital tract, and they can be affected by antibiotics.
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“[Antibiotics] alter the gut and vaginal microbiome, which can influence hormone metabolism, including how estrogen is processed in the body,” says Cookingham. “Some antibiotics may also affect inflammatory pathways that are important for embryo implantation, but these effects are not universal, and many antibiotics appear neutral or even protective in some studies.”
