Where have all the babies gone? HIV and fertility in Uganda

Women with HIV tend to have fewer babies. Are they less likely to get pregnant? Or do they have a greater risk of miscarriage or stillbirth? Researchers at the UK Medical Research Council Programme on AIDS in Uganda tried to answer these questions by following a group of 191 women in the south-west of the country.

They offered routine clinic visits every three months to 92HIV-positive and 99 negative women over nearly 11 years. During this time,there were 216 pregnancies in 104 women. Analysing data, including HIV statusand the incidence and outcomes of pregnancies, the researchers report that:

• 40 percent of the HIV-positive women had died bythe end of the study.
• The frequency of sexual intercourse decreaseswith advancing HIV disease.
• Overall, the odds of a woman with HIV beingpregnant are around half those for HIV-negative women.
• The likelihood of pregnancy decreases as thedisease worsens, whether this is measured by clinical stage, CD4 count (theimmune status of a patient), time from becoming HIV-positive or time before anAIDS diagnosis. There are very few pregnancies in the advanced stages of thedisease.
• There were 183 live births, 21 spontaneousabortions and 12 stillbirths or early neonatal deaths. HIV-infected women havea higher risk of foetal loss, even at the earliest stages of HIV infection.

This study shows that fertility decreases from the earlieststage of HIV infection, due to fewer pregnancies and increased foetal loss. Thisinformation will help to predict numbers of orphans due to AIDS and the ratesof HIV infection in children. It also shows that the estimation of general HIV ratesfrom antenatal clinic (ANC) data is not as straightforward as it seems. If HIV-positivewomen have lower fertility, they are less likely to attend ANC, and so thesedata may underestimate HIV rates in the general population. However, otherstudies have shown that women with lower fertility are more likely to becomeHIV-infected. Possible explanations include illness in their partners, othersexually transmitted infections, or the cultural pressure for women to havechildren in many African societies may push them towards more risky behaviour,such as having extra sexual partners.