Association between prematurity and maternal anemia in Venezuelan pregnant women during third trimester at labor.

To determine the association and its magnitude between prematurity and anemia in women in their third trimester of pregnancy and at labor. An incident case-control study was conducted using 2 controls per case. Data was obtained in a tertiary hospital in Valencia, Venezuela. A total of 543 women who delivered between May and December 1996 entered into the study. Women having a preterm delivery, less than 37 weeks of gestation at delivery, were defined as cases (n = 181). Anemia was defined according to WHO as Hb less than 11 g/dL. Logistic regression was used to analyze the data and likelihood ratio test was done for model comparison. Maternal anemia was found to be significantly associated with prematurity (Odds Ratio: 1.70; 95% CI = 1.18 to 2.57 P = .001), after adjusting for Placental Abruption, PROM, Previous Premature Labor, Prenatal Care Visits, and Uterine Bleeding during more than one trimester. Maternal anemia at the end of the third trimester of pregnancy, at labor, was associated with an increased risk of prematurity.