Prevention of mother-to-child transmission

Prevention of mother-to-child transmission

Antiretroviral therapy and preterm delivery- a pooled analysis of data from the United States and Europe.

The objective of the study was to investigate reported differences in the association between antiretroviral therapy in pregnancy and the risk of preterm delivery among HIV-infected women. The study is a combined analysis of data from three observational studies conducted in USA and Europe. A total of 19 585 singleton infants born to HIV-infected women, 1990-2006 were included in the study. Data from the Paediatric Spectrum of HIV Disease project (PSD), a US monitoring study, the European Collaborative Study (ECS), a consented cohort study, and the National Study of HIV in Pregnancy and Childhood (NSHPC), the United Kingdom and Ireland surveillance study. The main outcome measure was preterm delivery rate (<37>. Compared with monotherapy, optional antiretroviral therapy (3 or more days) was associated with increased preterm delivery risk in the ECS (adjusted odds ratio [AOR] 2.40, 95% CI 1.49-3.86) and NSHPC (AOR 1.43, 95% CI 1.10-1.86), but not in the PSD (AOR 0.92, 95% CI 0.67-1.26), after adjusting for relevant covariates. Because of heterogeneity, data were not pooled for this comparison, but heterogeneity disappeared when optional antiretroviral therapy was compared with dual therapy (P = 0.26). In a pooled analysis, optional antiretroviral therapy was associated with 1.5-fold increased odds of preterm delivery compared with dual therapy (95% CI 1.19-1.87, P = 0.001), after adjusting for covariates. Heterogeneity in the association between optional antiretroviral therapy and preterm delivery was not explained by study design, adjustment for confounders or a standard analytical approach, but may have been the result of substantial differences in populations and data collected. The pooled analysis comparing optional antiretroviral therapy with dual therapy showed an increased risk of preterm delivery associated with antiretroviral therapy with three or more drugs.

Editors’ note: This was a challenging task – interrogating three large observational studies in Europe, the United States of America, and the United Kingdom/Ireland with very different methodologies about whether antiretroviral therapy increases the risk of preterm delivery. Mother-to-child transmission has decreased to 1-2% in most resource-rich countries with women either already being treated with three or more antiretroviral drugs when they conceive or prescribed them to reduce transmission during pregnancy and childbirth. Although the pooled analysis here did find an increased risk of preterm delivery when the mother was taking three or more drugs compared with dual therapy, the benefits of optimal antiretroviral therapy for maternal health and reduced HIV transmission are evident. Only if a woman does not require antiretroviral treatment for her own health would the UK selective approach of zidovudine monotherapy for these women with elective caesarean section be an option.