Variations in maternal serum zinc during pregnancy and correlation to congenital malformations, dysmaturity, and abnormal parturition

Abstract

Serum zinc concentrations in 234 gravidae showed a gradual fall during the first and second trimesters. From the 25th week of gestation until delivery there is a levelling out of mean zinc values. No correlations between serum zinc, serum HCS, or urinary excretion of oestriol were found. Women with mature infants born by normal delivery showed significantly higher serum zinc during pregnancy than women with abnormal deliveries and/or abnormally developed infants (p less than 0.001). Eight infants showed congenital malformations. Five of the 8 mothers showed the lowest serum zinc concentrations recorded during respective week of pregnancy. A diabetic woman gave birth to an immature infant with multiple skeletal malformations. She showed the lowest serum zinc in the 21st week, and at the same time a very low alkaline phosphatase activity. Her serum proteins and serum HCS were normal. Women with dysmature infants showed significantly lower zinc values during pregnancy (p less than 0.02) than women with mature infants born by normal delivery. Data from studies on zinc metabolism show that there is a requirement of at least 375 mg of zinc during pregnancy in order to meet the demands of normal weight gain. Teenagers, women with multiple pregnancies, women with impaired intestinal absorption due to disease or drugs and in particular women with a low-protein, high-phytate diet seem to risk developing zinc deficiency during pregnancy.