Total homocyst(e)ine in plasma and amniotic fluid of pregnant women.

Total homocyst(e)ine was determined by the quantitation of protein-bound homocyst(e)ine in the stored plasma and amniotic fluid from 25 pregnant women and in the stored plasma from 17 nonpregnant women. The mean +/- SE of plasma total homocyst(e)ine was 29.8 +/- 2.4 nmol/g protein in pregnant women and 52.4 +/- 3.8 nmol/g protein in nonpregnant women. In contrast, the mean +/- SE of total homocyst(e)ine in amniotic fluid obtained at 16 weeks of gestation was 36.3 +/- 2.9 nmol/g protein. There was a statistically significant difference in the plasma total homocyst(e)ine concentrations from pregnant and nonpregnant women (P less than 0.01). Similarly, there was also a statistically significant difference between plasma total homocyst(e)ine from nonpregnant women and amniotic fluid total homocyst(e)ine (P less than 0.01). These observations suggested that the metabolism of homocysteine to cysteine was more efficient in pregnant women. In addition, the concentrations of total homocyst(e)ine in amniotic fluids were within narrow limits in normal pregnancies. Hence, total homocyst(e)ine concentration might be very valuable as a rapid assessment of fetuses for congenital defects of homocysteine metabolism.