New data from The European Collaborative Study presented at the 13th International AIDS Conference in Durban yesterday suggest that women who receive protease inhibitor-based combination therapy in pregnancy are two and a half times more likely to deliver prematurely than untreated women. Receipt of dual therapy or NNRTI-containing regimens was associated with a doubling of the prematurity rate. There was no difference, however, in the identified prevalence of birth abnormalities between newborns exposed to antiretroviral therapy in utero and those who were not.
Evidence of a possible association between use of HAART during pregnancy and prematurity was first reported by a Swiss team at the Geneva World AIDS Conference two years ago. Subsequent analysis from US cohorts did not support the association.
These new findings emerged from a Europe-wide observational study involving 2,728 HIV-positive pregnant women and 2,923 newborns. The cohort was mostly white (84%), and in the main, involved women resident in Italy and Spain.
The rate of vertical transmission within the cohort has fallen over time, from a rate of 15.9% in 1994 to 5.4% in 1998/99. Assessing the impact of a range of interventions, the study authors found transmission occurred in 16.1% of cases where avoidance of breastfeeding was the sole intervention practised. Where delivery was by elective c-section, the transmission rate fell to 10.2%; where the full 076 AZT prophylaxis regimen was administered to mother and baby, the rate was 6.1%; and where all three interventions were employed together, the rate fell to a low of 2.8%.
Thorne C et al. Antiretroviral therapy and caesarean section to reduce vertical transmission of HIV in Europe. 13th International Conference on AIDS, abstract MoOrC240, Durban, 9-14 July 2000.