Decreased fertility among HIV-1-infected women attending antenatal clinicsin three African cities

Population HIV prevalence estimates rely heavily on sentinel surveillance i n antenatal clinics (ANCs), but because HIV reduces fertility, these estima tes are biased. To aid interpretation of such data, we estimated HIV-associ ated fertility reduction among pregnant women in ANCs in Yaounde (Cameroon) , Kisumu (Kenya), and Ndola (Zambia), Data collection followed existing HN sentinel surveillance procedures as far as possible. HIV prevalence among t he women was 5.5% in Yaounde, 30.6% in Kisumu, and 27.3% in Ndola. The birt h interval was prolonged in HIV-positive multiparous women compared with HI V-negative multiparous women in all three sites: adjusted hazard ratios of pregnancy were 0.84 (95% confidence interval [CI]: 0.62-1.1) in Yaounde, 0. 82 (95% CI: 0.70-0.96) in Kisumu, and 0.74 (95% CI: 0.61-0.90) in Ndola, im plying estimated reductions in the risk of pregnancy in HIV-positive women of between 16% and 26%. For primiparous women, the interval between sexual debut and birth was longer in HIV-positive women than in HIV-negative women in all sites, although the association was lost in Ndola after adjusting f or age and other factors. Consistent results in different study sites help in the development of standard methods for improving ANC-based surveillance estimates of HIV prevalence. These may be easier to devise for multiparous women than for primiparous women.