Pregnancy doesn't boost HIV-1 risk

Center researchers were involved in a large study of African women that determined neither pregnancy nor lactation placed women at increased risk of HIV-1 acquisition.

Dr. Barbra Richardson and statistical research associate Jing Wang of the Public Health Sciences Division's Statistical Center for HIV/AIDS Research and Prevention (SCHARP) were co-authors on the study, which involved 4,415 women who made more than 31,000 visits to family-planning clinics in Uganda and Zimbabwe over a five-year period. The results were published in the May 11 issue of the journal AIDS.

The study refutes previous findings suggesting pregnancy is associated with an increased risk of contracting HIV-1. Those studies failed to evaluate whether behavior or the physiological changes linked to pregnancy cause any increase in risk.

In the current study, the scientists found that although pregnancy causes high levels of estrogen and progesterone related to structural and immunological changes, these differences did not appear to increase risk of HIV-1 infection.

"These results should provide reassurance for women desiring to become pregnant — and who would subsequently breastfeed — in areas with high HIV-1 prevalence," said Richardson, also part of the biostatistics department at the University of Washington.

However, pregnant women and their partners do not tend to use condoms consistently, and unprotected sex (unless in a known monogamous relationship) clearly raises risk of HIV-1 acquisition. Because there are high levels of HIV infection among pregnant and lactating women in these countries, the authors stressed that HIV-prevention programs must emphasize condom use to protect both mother and baby from HIV infection during and after pregnancy.

The National Institute of Child Health and Human Development at the National Institutes of Health funded the study, led by Dr. Charles Morrison of Family Health International.