Aim:Neural tube defects (NTDs) are the most common congenital anomalies, and prenatal prediction of the disease is essential. The underlying factors of the disease have not been determined. The aim of this study is to investigate the predictive role of thiol/disulfide homeostasis and Ischemia-modified albumin (IMA) levels for NTDs.Material and Methods:A total of 71 pregnant women (31 with NTD and 42 healthy controls) were enrolled in this study. This prospective case-control study included pregnant women with NTDs as the study group and randomly selected age-matched pregnant women with healthy fetuses as the control group. The two groups were compared on the basis of thiol/disulfide and IMA levels in the maternal and fetal samples.Results:No statistically significant difference in native thiol, total thiol, disulfide, and calculated ratios was observed between the groups. However, maternal IMA values were significantly higher in the study group. The IMA was proven to be a predictor with a sensitivity of 77.4% and specificity of 100% for NTDs at a cut-off value of 1.32.Conclusion:The examination of the maternal levels of IMA may be useful in the detection of NTDs.