Variability of total thiol compounds, oxidative and nitrosative stress in uncomplicated pregnant women and nonpregnant women.

Purpose: The objective of this study was to determine the changes in total plasma thiols (homocysteine, cysteine and cysteinylglycine), lipid peroxidation and nitric oxide concentrations during normal pregnancy.

Methods: These variables were measured in 28 uncomplicated pregnant women at first, second and third trimesters and in 19 nonpregnant women.

Results: The mean concentrations of homocysteine, cysteine and cysteinylglycine were significantly lower in all trimesters of pregnancy compared with nonpregnant controls. There was significant elevation in serum lipid peroxidation levels of pregnant women within first and third trimesters compared with nonpregnant women. In spite of increase in mean nitric oxide levels in pregnant women, this increase did not reach statistically significant levels.

Conclusion: This study provides information about the changes in plasma levels of many variables having important role in pregnancy complication during all trimesters in uncomplicated pregnancy compared with nonpregnant women.