TUAB0105
Share
 
Title
Dual epidemics: The impact of HIV and obesity on pregnancy outcomes among women in South Africa
Presenter
Angela Bengtson
Authors
A. Bengtson1, T. Phillips2, S. le Roux2, E.J. Abrams3, L. Myer2
Institutions
1Brown University School of Public Health, Department of Epidemiology, Providence, United States, 2University of Cape Town, Cape Town, South Africa, 3Columbia University, Department of Epidemiology and Pediatrics, New York, United States

Background: South Africa faces dual epidemics of HIV and obesity. However, little research has explored the impact of HIV and obesity on pregnancy outcomes.
Methods: We followed HIV-uninfected and HIV-infected pregnant women initiating antiretroviral therapy (ART) from first antenatal visit (ANC; baseline) through 12-months postpartum. At baseline, gestational age (GA) was estimated using ultrasound. Maternal anthropometry was measured at baseline and 12-months postpartum. Body mass index (BMI) was categorized as underweight (< 18.5 kg/m2), normal (18.5-< 25.0), overweight (25.0-< 30.0) and obese (>30.0). We used modified Poisson regression to estimate associations between BMI category and adverse pregnancy outcomes, and explored modification by HIV-status.
Results: We included 884 women (HIV-infected 53% and HIV-uninfected 47%). At baseline, 39% of women were obese and 3% underweight. Overall, 11% of infants were preterm (< 37 weeks'' gestation, n=96), 11% were low birthweight (LBW, < 2500 g, n=100), 12% were small for GA (SGA, < 10th percentile for GA, n=102) and 11% were large for GA (LGA, >90th percentile for GA, n=95). In multivariable analyses, overall obesity was not associated with preterm birth (RR 0.89, 95% CI 0.53, 1.50) or LGA (RR 1.39, 95% CI 0.86, 2.25). Among HIV-uninfected women, obesity was associated with LGA (RR 2.15, 95% CI 1.15, 4.02), while being underweight increased the risk of LBW (RR 3.55, 95% CI 0.76, 16.60) and SGA (RR 1.86 95%, CI 0.49, 6.99), although estimates were imprecise. Among HIV-infected women, normal BMI women had the highest risk of LBW (19%) and SGA (15%) and few infants (6%) were LGA (Figure).
Conclusions: In our population, associations between BMI and adverse pregnancy outcomes differed by HIV-status. Among HIV-uninfected women, being obese or underweight may have increased the likelihood of several adverse pregnancy outcomes. Conversely, HIV-infected women at normal BMI were at higher risk of adverse outcomes, including LBW and SGA.


Figure. Adverse pregnancy outcomes by body mass index (BMI) category for 884 pregnant women
[Figure. Adverse pregnancy outcomes by body mass index (BMI) category for 884 pregnant women]