AIDS 2016: Study Looks at Use of HIV PrEP Before and During Pregnancy and Breastfeeding

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Truvada for pre-exposure prophylaxis (PrEP) when it was offered as an additional tool for preventing HIV infection during the pre-conception period, pregnancy, and breastfeeding, according to study findings presented at the 21st International AIDS Conference (AIDS 2016) last month in Durban and published in the July 19 online edition of the American Journal of Obstetrics and Gynecology.

Transmission of HIV to the negative partner is a concern when serodiscordant heterosexual couples wish to conceive. Some couples opt for assisted reproductive technology such as "sperm washing" (separating individual sperm from semen) and artificial insemination, but these are expensive and not widely available.

Given the development of highly effective antiretroviral therapy (ART) that maintains viral suppression -- and the growing recognition that people on treatment with undetectable viral load probably cannot transmit HIV through sex -- "treatment as prevention" may be enough to protect the HIV-negative partner when trying to conceive naturally. But adding PrEP offers an extra measure of protection, for example if the positive partner misses medication doses or experiences viral "blips" for other reasons. If the woman is HIV-negative, protecting her from infection also protects the baby, as recent infection is associated with high viral load that makes mother-to-child HIV transmission more likely.

Once-daily Truvada (tenofovir/emtricitabine) was approved for HIV prevention based on findings from clinical trials, including the iPrEx study of mostly gay and bisexual men and the Partners PrEP study of serodiscordant heterosexual couples, showing that PrEP reduces the risk of HIV infection by 90% or more if used consistently.

To date there have been no randomized controlled studies of Truvada or tenofovir PrEP for pregnant women or those trying to conceive; these are unlikely in the future for ethical and logistical reasons. In PrEP clinical trials women generally stopped the drugs if they became pregnant, and there are no published reports of PrEP use after 7 weeks gestation or during lactation. 


However, tenofovir disoproxil fumarate and emtricitabine have been used by thousands of HIV-positive pregnant women over many years as part of antiretroviral treatment. Observational studies and data from the Antiretroviral Pregnancy Registry do not show increased likelihood of birth defects or adverse pregnancy outcomes. These drugs are regarded as generally safe and well-tolerated for both mothers and fetuses, though there is some evidence that infants born to women who take tenofovir during pregnancy may be smaller and have reduced bone density. The Microbicide Trials Network's ongoing EMBRACE study (MTN-016) hopes to shed more light on the safety of PrEP during pregnancy.

Dominika Seidman from the University of California at San Francisco, Shannon Weber of HIVE (who presented the findings at AIDS 2016), and colleagues aimed to characterize use of Truvada for PrEP and to identify gaps in HIV prevention services for women at risk of HIV before conception and during pregnancy and breastfeeding.

Pregnancy is an important opportunity to assess women for HIV risk. Many women who do not otherwise receive regular medical care do seek care when they become pregnant, and many may remain at ongoing risk for HIV infection after giving birth.

The researchers performed a retrospective chart review of 27 women considered to be at "substantial risk" for HIV infection who received care at 2 centers -- the University of California at San Francisco and Montefiore Medical Center in the Bronx, New York City -- between 2010 and 2015. If eligible they were referred to specialty clinics for women living with or at risk of HIV that started offering PrEP in 2010

Women were identified by clinicians, health educators, and health departments. The median time from identification as being at "substantial risk" to consultation was 30 days, and 2 women were lost to follow-up before consultation.

About two-thirds (18 women) were identified when they were already pregnant, at a median of 5 months gestation; none had received counseling about safer conception to reduce HIV risk. About a third (8 women) were identified pre-conception and 1 was identified during the post-partum period.

The median age was 27 years; 12 were Latina, 5 were black, 4 were white, 2 were Asian, and 4 were of other races/ethnicities. Just over half had unstable housing, 22% had ongoing intimate partner violence, 22% were active substance users, and 44% had a history of mental health issues.

All but 1 had HIV-positive partners, and the remaining woman had a male partner who had sex with men. Among the HIV-positive partners 19 (73%) were on ART and 11 (42%) had documented viral suppression; of the remainder, 10 (39%) had known detectable virus and 5 (19%) had unknown viral loads.

A majority of women were assessed for post-exposure prophylaxis (PEP), but nearly a third were not asked about their recent HIV exposures. Of those assessed, 7 were deemed eligible and 4 of them were offered PEP, but only 2 started taking it.

Among the 24 women who were offered daily Truvada PrEP, 16 (67%) chose to use it. Among the rest, two-thirds chose to use condoms, over half relied on their partner's treatment-as-prevention, and a fifth relied on abstinence. The likelihood of accepting PrEP was similar before conception and during pregnancy.

The median length of time on PrEP was 30 weeks. Half the women reported some challenges maintaining good adherence, with a third each citing side effects, social stressors, and difficulty taking daily pills. The researchers did not identify any PrEP-related pregnancy complications. There was only 1 HIV seroconversion, in a woman not taking PrEP.

Half the women on PrEP chose to breastfeed, as did half of those not taking PrEP. Among the women who were in care at the time of delivery, half did not attend a post-partum follow-up visit, so their long-term outcomes are unknown. 

In their conference poster the researchers described 3 "missed opportunities":

"Women at 2 United States centers frequently chose to use pre-exposure prophylaxis for HIV prevention when it was offered preconception and during pregnancy and lactation," the study authors concluded.

"Further research and education are needed to close critical gaps in screening for women who are at risk of HIV for pre- and post-exposure prophylaxis eligibility and gaps in care linkage before and during pregnancy and lactation," they added. "Post-partum women are particularly vulnerable to loss-to-follow-up and miss opportunities for safe and effective HIV prevention."

8/25/16

References

D Seidman, S Weber, K Oza, et al. Use of HIV pre-exposure prophylaxis during pregnancy and lactation at 2 U.S. centers. 21st International AIDS Conference. Durban, July 18-22, 2016. Abstract WEPEC195.

D Seidman, S Weber, MT Timoney, et al. Use of HIV pre-exposure prophylaxis during the preconception, antepartum and postpartum periods at two United States medical centers. American Journal of Obstetrics and Gynecology. July 19, 2016 (online ahead of print).