Fetal and maternal serum copper levels before and during labor in normal and complicated pregnancies.

The effect of labor on maternal serum copper levels was determined in normal and complicated pregnancies. The mean value +/- SD (3.16 +/- 0.48 micrograms/ml) in 82 clinically normal subjects at term during labor was compared with that (2.22 +/- 0.49 micrograms/ml) obtained from 50 controls matched for gestational age who were not in labor. Similarly, the mean value in labor (3.56 +/- 0.46 micrograms/ml) in 25 subjects with a complicated pregnancy was compared with that (2.87 +/- 0.43 micrograms/ml) obtained from 25 similar subjects prior to labor. A statistically significant difference (P less than .001) was observed in both comparisons. Copper levels in the corresponding fetal serum from the subjects in labor (normal and complicated) were compared with those of the maternal serum samples. The mean value of fetal serum samples in mothers with complications was higher than that in normal mothers, but the difference was not statistically significant. This trend of a rise in serum copper level during labor was further confirmed by analysis of the same subject during and before labor in normal (12 subjects) and complicated pregnancies (9 subjects). Moreover, maternal serum estriol and estetrol levels were determined from the same samples in the 4 groups to find a possible relationship with the corresponding copper levels. No statistically significant correlation was noted. A possible explanation for the rise of the serum copper level with the onset of labor and its clinical implications are also discussed.