Over a quarter of HIV-positive pregnant women and half of those during the postpartum period aren't adhering to their antiretrovirals properly, putting them at risk of passing the virus along to their children, as well as experiencing treatment failure and developing drug resistance.

Publishing their findings in the journal AIDS, researchers from Johns Hopkins University Bloomberg School of Public Health conducted a review of 51 studies of over 20,000 HIV-positive pregnant women in the United States, Kenya, South Africa and Zambia. Only 73.5 percent of the pregnant women and 53 percent of those during postpartum were greater than 80 percent adherent to their meds.

“That really was for us quite a shock,” said lead researcher Jean Nachega, MD, PhD, an infectious disease internist and an associate professor at Johns Hopkins. “That's the population that should have optimum adherence, but the reality is just the opposite. Our paper was a wake-up call.”

Multiple factors influenced these troubling statistics: poverty, pill burden, drug and alcohol use, as well as mental health factors, most notably post-partum depression. On the other hand, women who disclosed their HIV status and who had a strong social support system had higher levels of adherence. Nachega said further research is urgently needed to design successful interventions for this population.