The maternal serum thiol/disulfide homeostasis is impaired in pregnancies complicated by idiopathic intrauterine growth restriction.

<bold>Purpose: </bold>To investigate the maternal serum thiol/disulfide homeostasis in pregnancies complicated by idiopathic intrauterine growth restriction (IUGR) and to compare the results with healthy pregnancies.<bold>Materials and Methods: </bold>This descriptive cohort study included 55 pregnant women complicated by idiopathic IUGR and 57 similar gestational aged healthy pregnant women in the third trimester of gestation. Maternal serum samples were collected at the day of diagnosis and the thiol/disulfide homeostasis was measured by using an automated assay method. The patients were followed up until delivery and perinatal outcomes were recorded.<bold>Results: </bold>Maternal serum native thiol (308.1 ± 40.7 μmol/L vs. 282.4 ± 60.6 μmol/L) and total thiol (346.8 ± 48.1 μmol/L vs. 324.0 ± 62.2 μmol/L) concentrations were significantly lower in IUGR group compared with healthy controls (p: .010 and p: .032, respectively), whereas disulfide (19.3 ± 8.7 μmol/L vs. 20.8 ± 7.8 μmol/L) concentrations were similar between the groups (p: .350). Maternal serum disulfide/native thiol and disulfide/total thiol ratios were higher in IUGR group compared with healthy controls (p: .014 and p: .017, respectively), whereas native thiol/total thiol ratio was significantly lower in IUGR group compared with healthy controls (p: .016).<bold>Conclusions: </bold>This study suggests that there is an impaired maternal thiol/disulfide homeostasis in pregnancies complicated by idiopathic IUGR during the third trimester of gestation. [ABSTRACT FROM AUTHOR]