Doxycycline Linked to Higher Pregnancy Loss Risk
A cohort study in Annals of Internal Medicine links early-pregnancy doxycycline use to pregnancy loss, with further research still needed.
Updated on Nov. 9, 2026 in Pregnancy
A cohort study published in Annals of Internal Medicine reports that doxycycline use in early pregnancy is associated with a higher risk of pregnancy loss. The study compared women exposed to doxycycline with women exposed to another antibiotic, focusing on respiratory tract infection and acne as common indications.
Why it matters
The findings add to questions about antibiotic safety in early pregnancy, a period when many women may be prescribed medications before they know they are pregnant. The study examined only pregnancy loss and provides no evidence about pregnancies that continue to term or about the fetus.
The evidence comes from a multi-database cohort study drawing on large clinical datasets, comparing doxycycline users with users of another antibiotic in two common indications. Whether the association reflects a causal effect, and whether it extends to babies' longer-term health, remains unresolved.
The players
Annals of Internal Medicine
A peer-reviewed medical journal published by the American College of Physicians that releases clinical research and reviews.
Janna Morrison
A researcher at Adelaide University who heads the Early Origins of Adult Health Research Group and commented on the study.
The details
Researchers led by Almut G. Winterstein analyzed clinical data as part of a post-marketing analysis focused on antibiotics. Adelaide University's Prof Janna Morrison, Head of the Early Origins of Adult Health Research Group, commented on the findings and their limitations; she declared no interests.
Timeline
Monday, November 9, 2026, 22:00 UK time: Study published in Annals of Internal Medicine.
Big Picture
The study applies post-marketing surveillance of large clinical datasets to a question that trial populations rarely address: pregnancy outcomes after routine antibiotic use. Pregnant women are typically excluded from pre-approval trials, so observational studies like this one are a main source of safety evidence for medications taken during pregnancy.
Pregnant people who have been prescribed doxycycline should discuss the findings and any alternatives with their clinician rather than stopping treatment on their own. The study does not establish that the drug causes pregnancy loss, so decisions should rest on individual medical advice.
The takeaway
Antibiotic choices in early pregnancy deserve careful clinical review, and patients should raise concerns with their doctor. Further research is needed before drawing firm conclusions about risk.
Further reading
For related context, explore more on Pregnancy health coverage.
More information
Read the original Annals of Internal Medicine doxycycline pregnancy loss study.
