HIV-positive women less likely to become pregnant and more likely to miscarry even if asymptomatic

HIV-positive women are less likely to get pregnant and more likely to have a miscarriage, according to a study conducted in Uganda and published in the March 26^th edition of AIDS.

Find out more: Adverse pregnancy and birth outcomes in women living with HIV

The study involved a total of 191 women aged between 15-49, who were enrolled in the Natural History Cohort, which recruited women from 15 neighbouring villages in south-west Uganda between 1990 and 2001. Women were seen every three months, and were asked to complete a questionnaire about their recent sexual behaviour, fluctuation in menstrual cycle, pregnancy, miscarriage, births and illnesses. The women also underwent a physical examination at these visits. No anti-HIV medication was provided to any of the women in the study.

A total of 92 women were HIV-positive, and 99 women were HIV-negative. The HIV-positive women had the severity of their HIV infection graded using the World Health Organisation clinical staging system, which uses a four-grade system ranging from stage one (asymptomatic) to stage four (symptomatic illness including AIDS-defining illnesses). Every six months, blood samples were obtained from the HIV-positive women to measure their CD4 cell counts.

Of the HIV-positive women, 75 (85%) were classified as asymptomatic when they enrolled. 37 (40%) of the women progressed to AIDS, and a total of 40 (43%) HIV-positive women died during the course of the study.

The total number of clinic visits available for the investigators’ analysis was 2,524. They found that the frequency of sexual intercourse was lower in HIV-positive women, and that the frequency of sex diminished further with HIV disease progression. In comparison with HIV-negative women, the age-adjusted odds ratio for reporting sexual intercourse was 1.62 for stage one, 0.70 for stage two, 0.45 for stage three, and 0.14 for stage four.

HIV-positive women in all age groups (except 15-19) experienced fewer pregnancies. The adjusted odds ratio for pregnancy following HIV infection was 0.48. The investigators also found evidence of reduced incidence of pregnancy from the very earliest stages of asymptomatic HIV infection, with women classified as having WHO stage one HIV disease having an odds ratio of pregnancy of 0.58 compared to HIV-negative women.

Pregnancies in HIV-positive women were also associated with an increased risk of miscarriage (odds ratio 3.43). Because there were very few pregnancies in women with advanced HIV infection, it was not possible for the investigators to say if the risk of miscarriage increased with advanced stages of HIV disease. However, the investigators did find that the risk of miscarriage increased from the very earliest stages of asymptomatic HIV infection, with women with WHO stage one HIV disease having an odds ratio of 5.38 compared to HIV-negative women.

What’s more, pregnancy was less likely to result in live births in HIV-positive women than in HIV-negative women, even in those women with asymptomatic HIV infection (rate ratio 0.55). The rate of live births diminished even further as HIV disease progressed.

The investigators comment, “HIV disease progression is associated with a reduction in fertility. This reduction is present from the earliest asymptomatic stages of HIV infection, resulting from both a reduced incidence in recognised pregnancy and increased risk of fetal loss.”

The overall reduced fertility rate in HIV-positive women of 0.53 was greater than the 0.73 found in the investigators’ pre-1997 study. This reduction did not appear to be due to more women progressing to AIDS, or to a tendency to reduced fertility in HIV-positive women overall. However, the investigators speculate that it could be an interaction between increasing age and advancing HIV disease.

No information was gathered on women’s desire to become pregnant, and the investigators suggest that the diminished frequency of sexual intercourse and reduced rate of conception seen in HIV-positive women could be because these women were making efforts not to become pregnant.

Further information on this website

Pregnancy and conception - factsheet

HIV main infectious cause of death amongst pregnant South African women - news story