Cigarette smoking and fetal morbidity outcomes in a large cohort of HIV-infected mothers.

Background: Reproductive-age women comprise approximately 25% of all persons living with HIV/AIDS in the United States. HIV infection and smoking during pregnancy are independent risk factors for adverse fetal outcomes. We examined predictors of fetal growth restriction among infants born to HIV-infected mothers who smoke cigarettes in pregnancy.

Methods: We analyzed hospital discharge data linked to birth records from the state of Florida for 1998-2007 (N = 1,645,209). The outcomes of interest included: low and very low birth weight (LBW and VLBW), preterm and very preterm birth (PTB and VPTB), and small for gestational age (SGA). We calculated adjusted rate ratios (ARR) for these outcomes by HIV/AIDS status, smoking status, and sociodemographic variables. We also examined the association between the observed fetal morbidity outcomes and the interaction between HIV/AIDS and smoking status. We employed the generalized estimating equation framework to correct for intracluster correlations.

Results: All fetal morbidity outcomes were more common in mothers who had HIV/AIDS, regardless of smoking status. Maternal HIV status and cigarette use were independent predictors of LBW, PTB, and SGA, with morbidity effects more prominent in HIV-infected mothers who smoke cigarettes. We observed a significant interaction between maternal HIV and smoking status, in which mothers who were HIV positive and smoked during pregnancy experienced the greatest risks for LBW (ARR = 2.24 [1.89-2.65]), SGA (ARR = 1.95 [1.67-2.29]), and PTB (ARR = 1.70 [1.42-2.03]).

Conclusions: HIV-infected mothers who smoke cigarettes during pregnancy have a heightened risk for adverse fetal morbidity outcomes. There is a need for integration of smoking cessation interventions into ongoing HIV/AIDS programs.