Abstract
BACKGROUND: The risk of HIV transmission during pregnancy remains a concern in Cameroon. Recent estimates suggest a national HIV prevalence of approximately 4.5%, increasing the likelihood of vertical transmission. OBJECTIVE: To estimate HIV seroprevalence and identify sociodemographic and obstetric determinants of HIV infection among pregnant women attending antenatal care in Cameroon. METHODS: A cross-sectional study was conducted from September 2022 to June 2023 among pregnant women aged 15 years and above in 324 health facilities across eight regions. Consecutive voluntary sampling was used until the site-specific sample size was reached. Facilities were purposively selected based on monthly ANC attendance > 30. HIV screening followed the national algorithm. Multivariable Complementary Log-Log regression was used to identify factors associated with HIV infection, and adjusted prevalence ratios (aPRs) with 95% confidence intervals (CIs) were reported. Data were analysed using Excel and SPSS 27. RESULTS: Among 10,669 pregnant women (median age: 25 years), HIV prevalence was 2.6%. Younger women (< 25 years) were more likely to be HIV-positive (aPR = 1.20; 95% CI: 1.07–1.34). HIV positivity was lower among single (aPR = 0.80) and cohabiting women (aPR = 0.89) compared with married women. Women with primary (aPR = 0.82) or secondary education (aPR = 0.86) had lower HIV positivity than those with higher education. First-trimester ANC attendance was also associated with reduced HIV positivity (aPR = 0.88). Compared with Yaoundé, women in five other regions showed significantly lower HIV positivity (aPRs: 0.75–0.79). CONCLUSION: HIV prevalence among pregnant women in Cameroon is relatively low but remains unevenly distributed across regions and sociodemographic groups, with higher prevalence observed among married women and lower prevalence among women initiating antenatal care in the first trimester. Strengthening antenatal care as a platform for early HIV prevention, including timely counselling and partner testing, may help reduce these disparities and support progress toward eliminating mother-to-child transmission of HIV. CLINICAL TRIAL NUMBER: Not applicable. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12879-026-12656-5.