Zinc and birth weight in uncomplicated pregnancies.

The relationship between zinc status and birth weight in uncomplicated pregnancies was studied in 59 nulliparous and 27 multiparous Chinese women with singleton pregnancies, delivered at term. Maternal and umbilical cord blood, maternal pubic hair and a segment of the umbilical cord were collected at delivery for analysis. The zinc concentration was significantly higher (p less than 0.0001) in the plasma of newborn infants (13.9 +/- 2.8 mumol/l) than in maternal plasma (9.3 +/- 2.2 mumol/l), while the converse was found in tissue (60.8 +/- 17.0 vs 208.1 +/- 96.2 micrograms/g, p less than 0.0001). There was no significant correlation between birth weight and either maternal or newborn plasma or tissue zinc concentrations. Parity had no significant effect on maternal or newborn zinc concentrations in tissue and plasma.