Clinician-observed genital lesions among pregnant women in a high HIV/sexually transmitted infection prevalence setting

Objectives Clinician-observed external genital lesions may be incorporated into syndromic STI management, yet their prevalence and morphology in antenatal populations are poorly characterized. We aimed to describe the prevalence and types of clinician-observed genital lesions among pregnant women in a high HIV/STI prevalence setting and examine their distribution by laboratory-confirmed HIV, syphilis, and Chlamydia trachomatis, Neisseria gonorrhoeae, or Trichomonas vaginalis (CT/NG/TV ) status. Methods We analyzed clinical and laboratory data from the Philani Ndiphile antenatal STI screening study (2021–2025), conducted across four primary healthcare clinics in the Eastern Cape, South Africa (ClinicalTrials.gov identifier: NCT04446611). Among 2,247 pregnant women attending their first antenatal visit, trained clinicians documented the presence and morphology of external genital lesions during routine pelvic examination. Lesions were categorized as warts, inflammatory/dermatitis-like, ulcerative/erosive, boils/abscesses, scarring, cystic swelling, or other/unclassified. HIV and syphilis were diagnosed using rapid antibody testing and rapid treponemal tests; CT/NG/TV was detected by GeneXpert® molecular assay. Analyses used counts and proportions to characterize lesion prevalence overall and by infection status, with comparisons performed separately for HIV, syphilis, and CT/NG/TV . Results Overall, 61 participants (2.7%) had a clinician-observed genital lesion. Lesion prevalence was significantly higher among women living with HIV than among women without HIV (6.1% vs. 1.3%; p <0.001) and among women with, versus women without syphilis (11.9% vs. 2.4%; p < 0.001), but did not differ significantly between women with versus without CT/NG/TV (3.5% vs. 2.4%; p = 0.16). Warts were the most common lesion type overall and were disproportionately observed among women living with HIV. Among lesion-positive women within each infection group, ulcerative lesions were observed in 40% of those with syphilis, 12.5% of those living with HIV, and 19% of those with CT/NG/TV . Conclusions Clinician-observed genital lesions were uncommon in this antenatal cohort, and most laboratory-confirmed STIs were not accompanied by visible lesions. These findings highlight their limited overlap and support current guidelines emphasizing laboratory-based antenatal screening for HIV and syphilis, with expanded STI testing where diagnostic capacity permits.