By Will Boggs MD

NEW YORK (Reuters Health) - Women who initiate highly active antiretroviral therapy (HAART) or who have their first prenatal visit in the third trimester are more likely to have HIV detected at delivery, researchers say.

"We found that a quarter of women who started treatment in the third trimester of pregnancy had a detectable viral load at delivery," Dr. Ingrid T. Katz from Brigham and Women's Hospital in Boston told Reuters Health by email.

"Although the optimal timing is unknown, women should start before the third trimester and it's likely that the earlier they start, the better their outcome will be. However, it is important to note that the benefits of earlier HAART initiation must be weighed against potential risks of drug exposure to the fetus during the first trimester."

The use of HAART to suppress HIV replication is the mainstay in managing HIV in pregnant women, but despite its widespread use in the U.S., some women still have detectable viral load at delivery. Factors previously identified to be associated with detectable HIV at delivery include advanced HIV disease, late initiation of HAART, and inability to adhere to treatment.

Data for the new study came from the International Maternal, Pediatric, Adolescent AIDS Clinical Trials Group Protocol 1025.

Out of 671 women who initiated HAART for the first time during pregnancy, 88 (13.1%) had detectable viral load at delivery, but there was only one case (0.2%) of confirmed mother-to-child transmission of HIV, the researchers reported January 19 online in Annals of Internal Medicine.

Factors significantly associated with viral load detection at delivery included Black non-Hispanic race/ethnicity, lower educational level, pretreatment viral load during pregnancy above 10,000 copies/mL, initiation of HAART during the third trimester, first prenatal visit during the third trimester, and diagnosis of HIV before the current pregnancy.

Women with at least one treatment interruption were more than twice as likely to have detectable viral load at delivery as were women with no treatment interruption (28.2% vs 12.2%; p=0.004), and the proportion of women with detectable viral load at delivery was highest among those who reported nonadherence in the previous two weeks (19.3%) versus earlier (12.3%) or never (9.6%).

"We also found a difference in maternal outcomes based upon the type of drugs prescribed; namely, women who received less potent regimens had a higher probability of having detectable viral load at delivery," Dr. Katz said. "Finally, women who had higher pre-treatment viral loads were also at higher risk. These findings are important because they suggest that antiretroviral treatment can only achieve its optimal efficacy if HIV-positive individuals initiate treatment early and adhere to their medications throughout pregnancy, and underscore the importance of starting women on the most potent regimens available."

"Pregnancy is a critical period when we have an opportunity to engage women in care, and it is worrisome that many of these women had detectable viral loads despite being on treatment," she said. "One of the critical factors we need to determine is how to bring women into care earlier, and how to ensure that they continue receiving HIV care after delivery."

"Unfortunately, bringing people into care earlier is a complex problem," Dr. Katz explained. "There are a number of barriers, including: poverty, stigma, and difficulties accessing care. In our study black race and low educations (less than high school) were risk factors for having a detectable HIV-1 viral load at delivery. Solving this problem is going to require creative solutions that are patient-centered, such as peer-mentoring or educational outreach."

To get women into prenatal care earlier, Dr. Hoosen Coovadia from University of the Witwatersrand, Durban, South Africa suggested in email to Reuters Health, "Consolidate overall health services and ensure health system is fair and just, for example, through Universal Coverage and National Health Insurance; undertake community-based engagement and advocacy for attendance through the pregnancy cycle, from the antenatal period right through to...about two years and preferably until the child is five years old; and improved antenatal services by use of medical or trained nursing and community health workers; ensure proper access to health facilities for delivery and through the antenatal period; uncompromised infant and child care; financial allocations for these purposes."

"Maternal and Child Care should be integrated, and linked, for efficiency and effectiveness in protecting the lives and livelihood of mothers and their babies," he said.

SOURCE: http://bit.ly/1zsqNZK

Ann Intern Med 2015;162:90-99.