Objectives: The proportion of women delivering with known HIV status in sub-Saharan Africa is not well described. Risk of HIV transmission to newborns is a major concern, but there may also be increased risks for other adverse pregnancy outcomes.
Design: Hospital registry.
Setting: North East Tanzania (1999-2006).
Population: Singletons (n = 14,444).
Methods: Births were grouped by maternal HIV status and socio-demographic factors predicting HIV status, and associations between status and pregnancy outcomes were studied.
Main outcome measures: Maternal HIV status, perinatal mortality, prematurity, small for gestational age (SGA), birthweight and low Apgar score.
Results: The proportion of mothers with known HIV status increased from 7% before 2001 to 78% after 2004. Single motherhood, rural residence, low maternal education, maternal and paternal farming and higher paternal age were associated with unknown HIV status. About 7.4% (95% CI 6.7-8.1%) of women were HIV infected, with increased likelihood of infection with higher gravidity, single motherhood, rural residence, maternal business or farming occupations and paternal tribe. Compared with HIV-uninfected women, the untreated HIV-infected women had a higher risk of SGA births (adjusted risk ratio [ARR] 1.6; 95% CI 1.1-2.4), preterm birth (ARR 1.8; 95% CI 1.1-2.7) and perinatal death (ARR 1.9; 95% CI 0.95-3.8). Women with unknown HIV status had moderately increased risks. Treated HIV-infected women had a risk similar to that of the HIV-uninfected women for all outcomes, except for low Apgar score.
Conclusion: HIV testing and infection were associated with socio-demographic factors. Untreated HIV-infected women had higher risks of adverse pregnancy outcomes, and risks were also increased for women with unknown HIV status. There is still a need to increase availability of HIV testing, education and adequate therapy for pregnant women.