Researchers call for incident pregnancy planning in HIV clinical trials

Pregnancies occur even when contraceptive use is required for participation in clinical trials involving HIV treatment, especially among younger women in sub-Saharan Africa, a multinational study has found. Planning for this eventuality could allow the collection of data that might not otherwise be available, the study authors state.

About This Study

“Incidence and Predictors of Pregnancy in Women Enrolled in Large Multi-National HIV Treatment Trials of the AIDS Clinical Trials Group” was published online on Oct. 9, 2023, in Journal of Acquired Immune Deficiency Syndromes. The lead author is Ayotunde E. Omoz-Oarhe of the Clinical Trials Unit at Botswana Harvard AIDS Institute Partnership in Gaborone, Botswana.

Key Research Findings

This meta-analysis of four multi-country HIV treatment trials conducted by the AIDS Clinical Trials Group investigated how often participants became pregnant despite having agreed to use contraception and the baseline factors associated with these pregnancies.

The clinical trials included 1,626 women of reproductive potential, of which 143 became pregnant. Seventy-eight percent of participants were in sub-Saharan Africa, mainly South Africa, Malawi, and Zimbabwe; 8% of participants each were in Asia and South America, respectively; and 6% were in North America.

This study’s pregnancy incidence of 2.2 pregnancies/100 person years was significantly lower than in eight HIV prevention trials involving microbicides and also lower than the incidence in a meta-analysis of HIV clinical trials in sub-Saharan Africa. A younger age at study entry was a strong and consistent predictor of pregnancy in the study. Pregnancy incidence was found to be highest for those living in sub-Saharan Africa, compared to women in Asia and the Americas.

Discussion Highlights and Implications for Practice

Study limitations reported included the inclusion of a small number of trials and a lack of information on marital status, contraceptive methods, and other demographic characteristics. No information on potentially changing desires for pregnancy was collected. In addition, the trial included women between 45 and 55 years old who may have been premenopausal.

Clinical trials that require contraceptive use should still plan for incident pregnancies, the authors commented. This could allow for the collection of pregnancy data, if the participant continues in the trial, or of infant health data after early pregnancy exposure, if the participant discontinues the study drug.

In addition, not every interventional trial needs to exclude people who are or want to become pregnant. “Trial contraception requirements should ideally be based upon the best assessment of maternal and fetal risk and benefit in an individual study,” study authors noted.

By Barbara Jungwirth