Updated Statement - FSRH CEU Response to study: Unintended pregnancies and antibiotics
Date: 02 Feb 2021
Type: FSRH Clinical Guidance and Clinical Statements

Updated statement - FSRH CEU Response to study: Analysis of reports of unintended pregnancies associated with the combined use of non-enzyme inducing antibiotics and hormonal contraceptives
The journal BMJ Evidence Based Medicine recently published a study1—which has received some media attention—suggesting that concomitant use of non-enzyme inducing antibiotics could reduce the effectiveness of “hormonal contraceptives”.
In this updated FSRH CEU statement, a detailed critical assessment of the study is presented.
Given its substantial limitations, the findings from the Aronson and Ferner (2020) study are not scientifically robust enough to warrant any change to FSRH CEU guidance. FSRH CEU guidance remains that additional contraceptive precautions are not required when antibiotics are prescribed to users of hormonal contraception. In women using known enzyme-inducing medications long-term, including enzyme inducing antibiotics, the FSRH CEU recommends intrauterine contraception (IUC) or injectable contraception (DMPA).