Maternal anemia and preterm birth among women living with HIV in the United States

Background: Women living with HIV (WLHIV) have a higher prevalence of anemia than women without HIV, possibly related to the effects of HIV and antiretroviral medications. Objectives: To estimate the prevalence of anemia in the third trimester of pregnancy and the effect of anemia on preterm births in WLHIV in the longitudinal, US-based Pediatric HIV/AIDS Cohort Study (PHACS). Methods: During the third trimester, we obtained up to three 24-hour dietary recalls to estimate daily intakes of nutrients and measured serum concentrations of iron, vitamin B6, vitamin B12, zinc, folate, ferritin, total iron-binding capacity (TIBC), and high sensitivity C-reactive protein. Third trimester anemia was defined as hemoglobin < 11 g/d and iron-deficiency anemia (IDA) was defined as low ferritin, high TIBC, and low transferrin saturation. A preterm birth was defined as birth at < 37 completed weeks of gestation, regardless of etiology. We fit separate modified Poisson regression models for each outcome (anemia, preterm birth) and each main exposure, adjusted for confounders, and report adjusted prevalence ratios (aPR) and 95% CIs. Results: Of the 267 WLHIV, 50% were anemic in the third trimester, of whom 43.5% (n = 57/131) had IDA. On average, women with anemia were younger, were more likely to be black, started antiretroviral medications in the second trimester, had a low CD4 count (<200 cells/mm3) early in pregnancy, and were less likely to meet recommended intakes for iron, B6, and folate. The prevalence of anemia was greater in WLHIV with a low CD4 count (aPR= 1.65; 95% CI: 1.20-2.27) and high HIV viral load (>10,000 copies/mL; aPR = 1.38; 95% CI: 1.02-1.87). In total, 16% of women delivered preterm. Anemia was associated with a 2-fold (aPR = 2.04; 95% CI: 1.12-3.71) higher prevalence of preterm births. Conclusions: Anemia is common in pregnant WLHIV, highlighting the need to address the underlying factors and clinical outcomes of anemia in this population.