Factors influencing gestational age-adjusted birthweight in a national series of 600 newborns form mothers with HIV.

BACKGROUND: Few studies have assessed the determinants of birthweight in newborns from HIV-positive mothers in analyses that adjusted for different gestational age at delivery. METHOD: We calculated gestational age-adjusted birthweight Z-score values in a national series of 600 newborns from women with HIV and in 600 newborns form HIV-negative women matched for gender and gestational age. The determinants of Z-score values in newborns from HIV-positive mothers were assessed in univariate and multivariate regression analyses. RESULTS: Compared to newborns from HIV-negative women, newborns form HIV-positive women had significantly lower absolute birthweight (2799 vs 2887 g; p = .007) and birthweight Z score (-0.430 vs. -0.222; p < .001). AMong newborns from mother with HIV, the maternal characteristics associated with significantly lower Z-score values in univariate analyses were recent substance use (Z-score difference (ZSD) 0.612, 95% CI 0.359-0.864, p < .001), smoking <10 cigarettes/days (ZSD 0.323, 95% CI 0.129-0.518, p = .001), absence of pregnancies in the past (ZSD 0.200, 95% CI 0.050-0349, p = .009), non antiretroviral treatment in the past (ZSD 0.186, 95% CI 0.044-0.327, p = .010) and Caucasian ethnicity compared to Hispanic (ZSD =.248, 95% CI 0.022-0.475, p = .032). Body mass index (BMI) at conception and maternal glycemia levels during pregnancy were also significantly related to berthweight Z scores. Glycemia, BMI, and recent substance use maintained a significant association with Z score values in multivariate analyses. In the multivariate analysis, the only factors significantly associated with Z-score values below the 10th percentile were recent substance use (Adjusted odds ratio (AOR) 3.17, 95% CI 1.15-8.74) and smoking AOR 2.26, 95% CI 1.13-4.49). DISCUSSION: We identified serveral factors associated with gestationa age-adjusted birthweight in newborns from women with HIV. Smoking and substance use have a significant negative impact on intrauterine growth, which adds to an independent HIV-related effect on berthweight. Prevention and information on this issue should be reinforced in women with HIV of childbearing age to reduce the risk of negative outcomes in their offspring.