The effect of fetal infection with human immunodeficiency virus type 1 on birthweight and length of gestation

We sought to evaluate the effect of vertical transmission of human immunodeficiency virus type 1 (HIV-1) on birthweight and length of gestation. For this purpose we used maternal and pregnancy data of 559 HIV-1-seropositive pregnant women delivered at 13 Italian centers from 1985 to 1991. The mother-to-child transmission rate of HIV infection was 18.2% (84/461). After adjustment for potential confounders with multiple linear regression analysis, there were no differences in birthweight, gestational age, and proportion of expected birthweight (observed birthweight/expected birthweight) between infected and uninfected children. Intravenous drug abuse during current pregnancy was the factor which correlated best with a reduction in birthweight (mean reduction, 214.4 g; 95% confidence interval (CI), 61.7-367.1), length of gestation (mean reduction, 9.3 days; 95% CI, 3.9-14.7) and proportion of expected birthweight (mean reduction, 12.1%; 95% CI, 4.7-19.5%). In our population, HIV-1 infection of the fetus has little effect on length of gestation and birthweight.