Combination antiretroviral therapy and duration of pregnancy

Objective: To assess the association between type and timing of initiation of antiretroviral therapy in pregnancy and duration of pregnancy. Design: Prospective study. Methods: Data on 3920 mother-child pairs were examined (3075 mother-child p airs from the European Collaborative Study and 905 from the Swiss Mother Child HIV Cohort Study). Factors examined included gestational age, antiret roviral therapy during pregnancy, maternal CD4 count, viral load, illicit d rug use (IDU) and mode of delivery. Deliveries at less than 37 weeks were d efined as premature. Results: The prematurity rate was 17% and median gestational age 39 weeks. Twenty-three per cent (896 of 3920) of women received antiretroviral therap y during pregnancy: 64% (573 of 896) zidovudine monotherapy, 24% (215) comb ination therapy without protease inhibitors (PI) and 12% (108) combination therapy with PI. In multivariate analysis, adjusted for maternal CD4 count and IDU, odds ratio (OR) of prematurity was 2.60 [95% confidence interval ( CI), 1.43-4.75] and 1.82 (95% CI, 1.13-2.92) for infants exposed to combina tion therapy with and without a PI, respectively, compared to no treatment. Exposure to monotherapy was not associated with prematurity, but severe im munosuppression and IDU in pregnancy were. Women on combination therapy fro m before pregnancy were twice as likely to deliver prematurely as those sta rting therapy in the third trimester (OR, 2.17; 95% Cl, 1.034.58). Conclusions: Pregnancy issues should be discussed when making decisions abo ut initiation of combination antiretroviral therapy for HIV-infected women. Elective caesarean section to reduce vertical transmission at 36 weeks rat her than 38 weeks may be advisable in women on combination therapy with PI. (C) 2000 Lippincott Williams & Wilkins.