Serum Zinc & Iron in the First Half of Pregnancy and Their Relationship with Preterm Delivery: A Prospective Longitudinal Study

Preterm delivery is a critical factor in neonatal morbidity & mortality. The present study was performed to determine the relationship between serum level of zinc& iron and preterm delivery. This cohort study was conducted, via multi-stage sampling, on 1033 pregnant women referred to the prenatal centers of Tehran, Iran. The instrument was demographic- productivity questionnaire completed within the14th-20th weeks of gestation. Serum level of zinc & iron was measured by spectrophotometric atomic absorption method and Ferene test, respectively. To analyze the data, we used T test, χ2 and logistic regression, by SPSS16 software. The incidence of preterm delivery was 10.5%. This rate increased to 12.5% and 18.2% in lack of iron and zinc, respectively. There was no significant link between lack of zinc level and preterm delivery (P>0.05), But the relationship between lack of iron and preterm delivery was significant (P< 0.05). Based on logistic regression, there was higher risk of preterm delivery if iron serum level was low. [P=0.005, OR=2.16, cl (1.26-3, 69)]. Given the high impact of lack of iron on preterm delivery, we recommend that the factors effective on intake & absorb of iron be emphasized in reproductive education.