Oxidative/nitrosative stress increased the risk of recurrent pregnancy loss–Taiwan Recurrent Pregnancy Loss and Environmental Study (TREPLES)

Abstract

Objective

Oxidative stress biomarkers (OSBs) may be strongly associated with disease progression and recurrent pregnancy loss (RPL). However, the research on associations of most OSBs (e.g., 8-nitroguanine [8-NO₂Gua] and 4-hydroxy-2-nonenal-mercapturic acid [HNE-MA]) with RPL is limited. Therefore, we aimed to investigate the effect of OSBs exposure on RPL risk by performing a case-control study.

Material and methods

We use our established dataset, Taiwan Recurrent Pregnancy Loss and Environmental Study (TREPLES), which included 514 Taiwanese reproductive age women (aged 20–50 years; 397 cases and 117 controls) from National Cheng Kung University Hospital. RPL is clinically defined by a history of two or more consecutive miscarriages, where a miscarriage is defined as the termination of pregnancy before 20 weeks of gestation. The urinary levels of several OSBs (e.g., 8-hydroxy-2′-deoxyguanosine [8-OHdG], 8-NO₂Gua, 8-isoprostaglandin F_{2α [}8-isoPGF2_α], and HNE-MA) and malondialdehyde (MDA) were measured using isotope dilution liquid chromatography-tandem mass spectrometry and thiobarbituric acid reactive substances, respectively.

Results

The median levels of 8-NO₂Gua (6.15 vs. 3.76 ng/mL) and HNE-MA (30.12 and 21.54 ng/mL) were significantly higher in the RPL group than in the control group. By categorizing the OSBs data into tertiles, after we adjusted for age and urine creatinine levels discovered that the RPL risk associated with 8-NO₂Gua and HNE-MA levels in the third tertile were approximately 2 times higher than those in the first tertile (8-NO₂Gua, adjusted OR = 3.27, 95 % CI = 1.66–6.43; HNE-MA, adjusted OR = 1.96, 95 % CI = 1.05–3.64; p < 0.05). These findings suggest that the oxidative stress biomarkers of 8-NO₂Gua and HNE-MA are risk factors for RPL.

Conclusion

Our findings indicate that specific OSBs are associated with an increased RPL risk, suggesting that reducing OSB levels can improve RPL risk. Nevertheless, more studies on preventive medicine are required to understand the exposure sources and adverse outcome pathways of OSBs associated with RPL.