Smoking alters the relationship between maternal zinc intake and biochemical indices of fetal zinc status

Abstract

Maternal smoking impairs fetal zinc status. This study was designed to clarify the effect of smoking on the relationship between maternal zinc intake and zinc status in mother and fetus. Zinc was measured with atomic-absorption spectroscopy. Statistical analyses consisted of descriptive statistics, simple correlations, and stepwise multiple regression. The results suggest that maternal plasma zinc, red blood cell zinc, and alkaline phosphatase at term are not related to maternal zinc intake. In the nonsmoking parturient both cord-vein plasma zinc and cord-vein alkaline phosphatase activity are positively related to maternal zinc intake. In the smoking parturient there is no relationship between maternal zinc intake and fetal zinc status except for a negative relation with cord-vein plasma zinc. Relations between maternal zinc intake and placental zinc can be shown with stepwise-multiple-regression techniques. The data suggests that maternal zinc intake is related not to maternal zinc status but to fetal zinc status in a normal pregnancy. The relation is altered in the pregnancy complicated by smoking.