Maternal hematologic changes during pregnancy and the effect of iron status on preterm delivery in a west Los Angeles population

This study was conducted to document the prevalence of anemia and high hema tocrit during pregnancy and examine their effect on delivering preterm in a predominantly Hispanic population. The sample consisted of women receiving prenatal care from the public health clinics in the West Los Angeles from 1983 to 1986 (n = 7589). Multivariate logistic regression was used to isola te the role of anemia and high hematocrit from other factors that may influ ence birth outcome. The prevalence of anemia was approximately 9% at the in itiation of prenatal care and at 28-32 weeks' gestation. Only anemia at 28- 32 weeks was significantly associated with a preterm birth, even after adju sting for several confounders [Adjusted Odds Ratio (AOR) 1.83 95% Cl = 1.21 , 2.77]. A high hematocrit that occurred in 9.6% of the population at 28-32 weeks was inversely associated with a preterm birth (AOR 0.78, 95% Cl = 0. 44, 1.39). There was little differentiation of these risk factors when anal yzing the etiological pathways of a preterm birth. These results indicate f or the first time in a predominantly Hispanic population that despite routi ne iron supplementation, anemia still occurs in pregnant women and it can p redict a preterm delivery.