Prevalence of Anemia Across Trimesters in Multiethnic Pregnant Women

Abstract

\n \n \n This study aimed to characterize prevalence and determinants of anemia in a multiethnic cohort of pregnant women.\n \n \n \n A retrospective medical chart review was undertaken of all deliveries occurring from 2011 to 2020 at Strong Memorial Hospital and Highland Hospital in Rochester, NY. Among a total of 53,642 deliveries, 42,289 occurred to women with no underlying health complications. Anemia was defined using the CDC criteria as <\xa011g/dL\xa0in\xa0the first (T1) and third trimesters (T3) and <\xa010.5\xa0g/dL in the second trimester (T2). Mean Hb concentration was compared between trimesters and racial groups by ANOVA and post-hoc pairwise comparisons. Relationships between prevalence of anemia by trimesters, racial groups, and BMI were examined by chi-square or t-tests. Logistic regression models were conducted to estimate the risk factors associated with anemia.\n \n \n \n Pregnant women had a mean age of 29.8\xa0± 5.5 y (range: 13−52 y) at delivery. The majority of women (66.8%) self-identified as white, 20.0% as black, 3.8% as Asian, and 9.4% as Other. Mean Hb concentrations significantly differed by trimester [12.6\xa0± 1.0, 11.5\xa0± 1.1, and 11.8\xa0± 1.3\xa0g/dL in T1, T2 and T3, respectively, p <\xa00.001]. Mean Hb was significantly lower in black women in each trimester by -0.8 (T1), -0.7 (T2), and -1.0\xa0g/dL (T3) compared to white women. White women had the highest Hb concentrations in T1 and T2 (12.8\xa0± 0.9, 11.8\xa0± 1.0\xa0g/dL) while Asian women had the highest Hb concentrations in T3 (12.2\xa0± 1.2\xa0g/dL, n\xa0=\xa01577, p <\xa00.001). The overall prevalence of anemia was 17.1%, which significantly increased across pregnancy [4.5% (T1), 16.4% (T2) and 25.2% (T3), p <\xa00.001]. Observed rates of anemia were higher than the estimated NHANES (1999–2006) prevalence in pregnant women. After stratifying by racial groups, higher BMI was significantly associated with a lower prevalence of anemia in T2 and T3 only in black women and in those whose race was categorized as Other.\n \n \n \n The prevalence of anemia was highest in black pregnant women in all trimesters, while it was lowest in white pregnant women in T1 and T2, and in Asians in T3. Risk factors associated with anemia included late gestation or self-reported race as black or Other.\n \n \n \n None.\n