Antiretroviral Therapy Interruption during Pregnancy Increases the Risk of Mother-to-Child HIV Transmission

Evidence continues to accumulate indicating that interruption of antiretroviral therapy (ART) has deleterious effects. According to an Italian study published in the March 23, 2009 issue of Clinical Infectious Diseases, stopping treatment during pregnancy can increase the risk of mother-to-child HIV transmission.

With prophylactic therapy, such as the ACTG 076 regimen of zidovudine (AZT; Retrovir) given during pregnancy, labor, and to the baby for 6 weeks after birth, the risk of perinatal transmission has decreased dramatically. But combination therapy can reduce the risk even further by fully suppressing HIV viral load, and the latest DHHS treatment guidelines recommend that pregnant women should receive a complete ART regimen even if they would not otherwise need treatment based on CD4 cell count.

Many experts, however, have traditionally advised pregnant women on ART to interrupt therapy during the first trimester, when the developing fetus is most susceptible to adverse effects of drug exposure. Although most HIV transmission is thought to occur during late pregnancy or delivery, this recommendation is not well supported by data.

In the present study, Luisa Galli and colleagues used logistic regression models to estimate adjusted odds ratios for factors potentially contributing to mother-to-child transmission, including maternal ART interruption, in a prospective cohort of pediatric patients in the Italian Register for HIV Infection in Children.


Based on these results, the study authors concluded, "Discontinuing ART during pregnancy increases the rate of mother-to-child transmission of HIV-1, either when ART is stopped in the first trimester and subsequently restarted or when it is interrupted in the third trimester."

"This finding supports recommendations to continue ART in pregnant women who are already receiving treatment for their health," they added.

The results are also compatible with the U.S. recommendation that untreated HIV positive women start combination ART during pregnancy even if they don't yet need treatment for their own health.

University of Florence and Centre for the Study and Prevention of Tumours, Research Institute of the Tuscany Region, Florence; University of Turin, Turin; Mangiagalli Hospital; University of Milan, Sacco Hospital and S. Paolo Hospital, Milan; University of Padua, Padua; Gemelli Hospital, Spallanzani Hospital and Bambino Gesù Children's Hospital, Rome; University of Brescia, Brescia; Federico II University, Naples; University of Pavia, Pavia; University of Modena, Modena; Hospital of Bergamo, Bergamo University of Bari, Bari, Italy.



L Galli, D Puliti, E Chiappini, and others.Is the Interruption of Antiretroviral Treatment During Pregnancy an Additional Major Risk Factor for Mother-to-Child Transmission of HIV Type 1? Clinical Infectious Diseases. March 23, 2009 (Epub ahead of print). (Abstract).