Hormonal Contraceptives Do Not Accelerate Disease Progression in HIV Positive Women

By Liz Highleyman

The natural history of HIV and its treatment have not been as well studied in women as in men. Past laboratory, animal, and human research has provided conflicting data about the effects of hormonal contraception -- such as the pill and implantable or injectable methods -- on HIV disease. While some studies have suggested hormonal contraception might increase susceptibility to HIV infection or accelerate disease progression in untreated women, others have not seen these effects.

In a presentation at the 16th Conference on Retroviruses and Opportunistic Infections (CROI 2009) last week in Montreal, Elizabeth Stringer of the University of Alabama described data from an analysis of the impact of contraception among participants in the MTCT Plus Initiative, a family-based HIV care and treatment program in Africa and Asia.

The study enrolled nearly 8000 women, followed from 2003 to 2008, of whom just over 4530 were included in the present analysis. These women were not yet on antiretroviral therapy (ART), were not pregnant, were at least 3 months post-partum, and had experience with a variety of birth control methods. The average age was about 28 years and the mean baseline CD4 cell count was approximately 420 cells/mm3.

At baseline, 3099 women (about 70%) reported using either no birth control or non-hormonal contraception -- such as condoms, an intrauterine device, or the rhythm method -- while 1060 (29%) used hormonal methods. In the latter group, 830 used progesterone-only injectables or implants and 226 used combination estrogen plus progesterone oral contraceptive pills. (Method was unknown for the remaining women).

The investigators used Cox regression to compare HIV disease progression -- defined as either death or becoming eligible for ART (CD4 count < 200 cells/mm3, WHO Stage IV disease, or WHO Stage III + CD4 count < 350 cells/mm3) according to type of contraception used at the time of enrollment. Since some women switched methods over time, they also performed a time-varying analysis in which women who switched contributed time to each exposure category.

Results

Overall, there was no evidence of hormonal contraception accelerating HIV disease progression.

A total of 66 women died and 881 became eligible for ART.

Using a reference hazard ratio of 1.0 for non-hormonal or no contraception:

Progesterone-only injectables and implants had an adjusted hazard ratio (AHR) for disease progression of 1.0 -- that is, no difference.

Combination oral contraceptive pills had an AHR of 0.90.

Risk factors for disease progression were:

CD4 count of 200-350 cells/mm3 (AHR 5.69);
WHO Stage II disease (AHR 1.52);
WHO Stage III disease (AHR 3.46).

Based on these results, the researchers concluded, "In contrast to some other, smaller studies, this multi-country cohort analysis suggests that hormonal contraception does not accelerate HIV disease progression."

While these results are encouraging, they added, "further research is needed to examine the potential influence of individual components of contraceptive agents on disease progression."

Speaking at a press conference about the findings, Stringer said, "Hormonal contraception appears to be safe in HIV-infected women, but more research is needed," for example on the potential link between hormones and inflammation.

2/17/09

Reference
E Stringer, M Sinkala, M Giganti, and others. Effect of Hormonal Contraception on HIV Disease Progression: A Multi-Country Cohort Analysis. 16th Conference on Retroviruses and Opportunistic Infections (CROI 2009). Montreal, Canada. February 8-11, 2009. Abstract 175.