Thiol/disulfide homeostasis in patients with idiopathic recurrent pregnancy loss assessed by a novel assay: Report of a preliminary study.

Abstract

To evaluate the relationship between idiopathic recurrent pregnancy loss (RPL) and oxidative stress (OS) by means of thiol/disulfide homeostasis via a novel technique. Thirty-nine pregnant women diagnosed with idiopathic RPL were compared with 50 healthy pregnant women without a history of abortion. Idiopathic RPL was defined as experiencing two or more consecutive miscarriages prior to 20 weeks of gestation with the presence of normal karyotypes of couple and/or abortus materials, negative maternal screening for anticardiolipin, anti β 2 glycoprotein antibodies and lupus anticoagulant, normal thyroid stimulating hormone, prolactin and hemoglobin A1C levels and normal pelvic sonography and/or hysterosalpingography. A new and fully automated method was used to measure plasma native thiol, total thiol and disulfide levels, based on the reduction of dynamic disulfide bonds to functional thiol groups by sodium borohydrate. Women with idiopathic RPL had significantly lower plasma levels of native thiol (341.89 ± 50.0 μmol/L vs. 390.84 ± 38.5 μmol/L, P < 0.001) and total thiol (386.18 ± 51.7 μmol/L vs. 435.78 ± 42.3 μmol/L, P < 0.001). Disulfide/thiol and disulfide/total thiol ratios were significantly higher in the study group. The native thiol/total thiol ratio was significantly lower in patients with idiopathic RPL. No difference was measured in disulfide, albumin and total protein plasma levels. The main outcome of our study indicates a relation between idiopathic RPL and OS. More importantly, the new method used in our study proposes a promising, practical and daily applicable test for evaluating patients with idiopathic RPL.