Risk factors for preterm birth, low birth weight, and intrauterine growth retardation in infants born to HIV-infected pregnant women receiving zidovudine

Abstract

To evaluate independent contributions of maternal factors to adverse pregnancy outcomes (APO) in HIV-infected women receiving antiretroviral therapy (ART). Risk factors for preterm birth (< 37 weeks gestation), low birth weight (LBW) (< 2500 g), and intrauterine growth retardation (IUGR) (birth weight < 10th percentile for gestational age) examined in 497 HIV-infected pregnant women enrolled in PACTG 185, a perinatal clinical trial. HIV RNA copy number, culture titer, and CD4 lymphocyte counts were measured during pregnancy. Information collected included antenatal use of cigarettes, alcohol, illicit drugs; ART; obstetric history and complications. Eighty-six percent were minority race/ethnicity; 86% received antenatal monotherapy, predominantly zidovudine (ZDV), and 14% received combination antiretrovirals. Preterm birth occurred in 17%, LBW in 13%, IUGR in 6%. Risk of preterm birth was independently associated with prior preterm birth [odds ratio (OR) 3.34; P < 0.001], multiple gestation (OR, 6.02; P = 0.011), antenatal alcohol use (OR, 1.91; P = 0.038), and antenatal diagnosis of genital herpes (OR, 0.24; P = 0.022) or pre-eclampsia (OR, 6.36; P = 0.025). LBW was associated with antenatal diagnosis of genital herpes (OR, 0.08; P = 0.014) and pre-eclampsia (OR, 5.25; P = 0.049), and baseline HIV culture titer (OR, 1.41; P = 0.037). IUGR was associated with multiple gestation (OR, 8.20; P = 0.010), antenatal cigarette use (OR, 3.60; P = 0.008), and pre-eclampsia (OR, 12.90; P = 0.007). Maternal immune status and HIV RNA copy number were not associated with APO. Risk factors for APO in antiretroviral treated HIV-infected women are similar to those reported for uninfected women. These data suggest that provision of prenatal care and ART may reduce APO.