Background We examined HIV prevalence trends over 4.5 years among women receiving antenatal care in Kinshasa, Democratic Republic of Congo, by geographic location, clinic management and urbanicity.

Methods Quarterly proportions and 95% confidence intervals (CIs) of pregnant women with HIV positive results were determined using aggregate service provision and uptake data from 22 maternity units that provided vertical HIV prevention services from October 2004 to March 2009. Assuming linearity, proportions were assessed for trend via the Cochran–Armitage test. Multivariable binomial regression was used to describe detailed prevalence trends.

Results HIV testing was offered to 220 006 pregnant women; 210 348 (95.6%) agreed to be tested and 191 216 (90.9%) received their results. A total of 3999 women were found to be HIV positive, a prevalence of 1.90% (95% CI: 1.84–1.96%). The median quarterly proportion of women testing positive for HIV was 1.94% (range: 1.44–2.44%). Prevalence was heterogeneous in terms of maternity management, urbanicity and geographic location. Modeling suggested that the overall prevalence dropped from 2.04% (95% CI: 1.92–2.16%) to 1.77% (95% CI: 1.66–1.88%) over 4.5 years, a relative decrease of 13.2% (95% CI: 3.53–22.9%). Trend testing corroborated this decline (P < 0.01).

Conclusions The decreasing HIV prevalence among Kinshasa antenatal care seekers is robust and encouraging. The relatively low prevalence and the weak existing healthcare system require prevention of mother-to-child transmission interventions that strengthen maternal and child healthcare service delivery. Complacency would be unwarranted: assuming a uniform national crude birth rate of 50/1000 and 1.8% antenatal HIV prevalence, approximately 7000 pregnant HIV infected women in Kinshasa, and 60 000 nationwide, are in need of care and prevention services yearly