First trimester serum zinc concentrations in human pregnancy.

Serum zinc concentrations in the 1st trimester of human pregnancy were evaluated in 106 women whose dates of conception were precisely determined by basal body temperature monitoring and human chorionic gonadotropin levels. Data are reported by intervals of postovulatory days. Sera were analyzed for zinc by atomic absorption spectrophotometry after acid digestion. Mean 1st trimester serum zinc concentrations, determined by 20-day increments from ovulation, were 0.97 +/- 0.22, 0.68 +/- 0.14, 0.77 +/- 0.18, and 0.70 +/- 0.15 micrograms/ml; differences between means were significant at p less than 0.005, less than 0.005, and less than 0.01, respectively. These differences could not be related to diet, supplement use, or hematocritic changes. No differences were apparent between diabetic and nondiabetic subjects. Of the 25 samples from women who aborted spontaneously, zinc concentration of seven were lower than interval means.