P370 What are the risk factors for Chlamydia in women attending an abortion service in the UK

Background The 2019 updated NICE abortion guidance suggested that prophylactic antibiotics should no longer be routinely given for medical abortions and instead recommended individual risk assessment. Untreated Chlamydia trachomatis is an important cause of severe infection post abortion. In 2002, 75 (7.5%) of 998 women having an abortion tested chlamydia-positive using a nucleic acid amplification test (NAAT). Women attending our abortion service have been tested for Chlamydia using a NAAT. We wished to obtain contemporary estimates of Chlamydia prevalence and examine associated risk factors. Methods Data from 13,427 women aged 15–50 years having an abortion between April 2010 and March 2020, was retrospectively analysed (SPSS, IBM). Ethics approval was sought and all data was anonymised. Results Of 13,337 with Chlamydia NAAT results available, 4.2% (565) were Chlamydia-positive. Chlamydia was associated with younger age (p Conclusion Chlamydia prevalence in women undergoing an abortion is lower than that observed in 2002 but is higher than the general population. Although Chlamydiawas associated with 2 or more partners in the previous year in women aged over 19 years, the association is weaker than that observed in the general population and no association was observed with partner change in women aged 15–19 years old