The maternal thiol/disulfide homeostasis does not change in pregnancies complicated by preterm prelabor rupture of membranes

Variation of the Oxidative Profile in Pregnant Women With and Without Gestational Complications

INTRODUCTION

Oxidative stress is closely related to the pathophysiology of gestation, where the placenta is susceptible to oxidative damage, contributing to the onset of gestational complications. Currently, few studies evaluate the use of oxidative markers for prediction of risk of gestational complications. However, there are some reports that suggest these biomarkers as potential prognostic biomarkers. Therefore, the objective of this study was to compare the biomarkers of oxidative stress from gestations with and without complications, and also evaluate the delta of variation in these markers from the first gestational trimester.

MATERIAL AND METHODS

A total of 45 pregnant women were evaluated during the three gestational trimesters, of whom 15 developed gestational complications by the end of gestation. The evaluated oxidative damage markers were thiobarbituric acid reactive substances and nitric oxide dosage. Evaluation of the antioxidant system was performed by the quantification of vitamin C, sulfhydryl groups, total antioxidant capacity, plasmatic iron reduction ability, the evaluation of catalase and delta-aminolevulinate dehydratase enzymatic activity.

RESULTS

According to the results, the markers of oxidative damage are increased, and the antioxidant profile decreased, in the third trimester of complicated pregnancies as compared to uncomplicated pregnancies. Moreover, the delta of variation in both oxidative damage markers and antioxidants was higher in complicated gestations as compared to uncomplicated gestations, thus suggesting a higher oxidative stress in pregnancies with complications.

CONCLUSIONS

Oxidative stress parameters appear altered in pregnant women with gestational complications. The markers to oxidative stress can be possible biomarkers, helping in understanding mechanisms underlying the associations between complications during pregnancy and various health outcomes.

The evaluation of maternal systemic thiol/disulphide homeostasis for the short-term prediction of preterm birth in women with threatened preterm labour: a pilot study

The aim of this study was to investigate maternal systemic thiol/disulphide homeostasis (TDH) for the short-term prediction of preterm birth in women with threatened preterm labour (TPL). This prospective study included 75 pregnant women whose pregnancies were complicated by TPL. Thirty-seven of them delivered within 7 days and 38 of them delivered beyond 7 days. Maternal serum samples were collected at the day of diagnosis and the TDH was measured. The maternal disulphide level was significantly higher in pregnant women who delivered within 7 days (25.0 ± 9.8 μmol/L vs 19.4 ± 9.8 μmol/L, p: .015). The threshold value of 22.1 μmol/L for maternal disulphide level predicted delivery within 7 days with 62.2% sensitivity and 60.5% specificity (area under curve 0.651, confidence interval 0.53-0.78). The likelihood ratios for short cervix (≤25 mm) and maternal disulphide level (≥22 μmol/L) to predict delivery within 7 days was found to be 8.7 and 7.3, respectively. The likelihood ratio of combining two tests to predict delivery within 7 days was found to be 11.4. The maternal TDH, which is an indicator of oxidative stress status in maternal compartment, is disturbed in TPL cases who delivered within 7 days. Elevated maternal disulphide level along with cervical length screening predicts a short latency period in pregnancies with TPL. IMPACT STATEMENTWhat is already known on this subject? Spontaneous preterm delivery is one of the major complication of pregnancy and the common cause of neonatal morbidity and mortality. Threatened preterm labour (TPL) is also a frequent complaint in obstetric emergency care units in all around the world. Triaging women with TPL is mandatory for planning further management therapies, since the most of them will eventually deliver at term. Only the measurement of cervical length in symptomatic women has moderate accuracy in predicting preterm delivery. Short cervix is described as an independent predictor of preterm delivery in women with TPL, its predictive accuracy as a single measurement is relatively limited. On this account, several potential markers like foetal fibronectin in the cervicovaginal fluid, salivary oestriol, prolactin in vaginal discharge, maternal serum calponin and interleukin-6 in the amniotic fluid were examined to predict preterm delivery in previous studies. However, none of them represented an excessive predictive accuracy like high sensitivity, PPV or NPV.What do the results of this study add? We report a method which has higher diagnostic and predictive performance to identifying TPL women with high risk of preterm delivery. According to the current literature, there are accumulated data about the correlation between oxidative stress (OS) and preterm delivery regardless of the amniotic membrane status. However, it is still debated whether OS is a trigger or a consequence of preterm delivery. Our study provides evidence for the first time that maternal serum thiol/disulphide homeostasis, which is an indicator of OS in maternal compartment, is disturbed in TPL cases who delivered within 7 days. The high disulphide level in maternal serum, along with cervical length measurement (short cervix) accurately predicts a short latency period in TPL cases.What are the implications of these findings for clinical practice and/or further research? This novel test combination (maternal serum disulphide level and cervical length measurement) could be used clinically to triage pregnant women presenting with TPL, avoiding overtreatment, unnecessary hospitalisations and increased medical costs. The future research would be addressed on reducing maternal OS by using new antioxidant treatment strategies to improve perinatal and long-term childhood outcomes.

Measuring the status of maternal serum thiol/disulfide couples in the diagnosis and/or the determination of the severity of late-onset preeclampsia

OBJECTIVE

Preeclampsia (PrE) is a pregnancy-related disorder. PrE affects the health of the mother and/or the fetus binomial with short and/or long-term consequences. The role of oxidant/antioxidant molecules and aberrant maternal inflammation in PrE has been documented. However, the importance of antioxidant molecules such as thiols has been poorly documented. In this research, a possible link between serum thiols levels and the diagnosis/severity of late-onset PrE (L-PrE) was investigated.

MATERIALS AND METHODS

We examined maternal serum native thiols, disulfide, total thiols levels, and their ratios in pregnant women with (n = 51) and without L-PrE (n = 50). The levels of these three markers were measured using spectrophotometric assays and compared.

RESULTS

There were significant differences in terms of serum native and total thiols levels between patients with L-PrE and healthy pregnant women (p = .001, p = .008, respectively). Disulfide levels were not different in either group (p = 0.729). There was no difference between total thiols, native thiols, disulfide concentrations, and their ratios in patients with mild (23 patients) and severe (27 patients) preeclampsia in L-PrE (p ≥ .05). A significant discriminative role of native and total thiols for the presence of L-PrE, with cutoff values of 175.86 μmol/L and 296.73 μmol/L, respectively, were revealed in ROC curve analysis.

CONCLUSIONS

Lower concentrations of total/native thiols were linked with the development of L-PrE. However, there is still a need for more clinically useful biomarkers/molecules and management strategies in PrE.

Maternal serum thiol/disulfide homeostasis in pregnancies complicated by fetal hypoxia

We aimed to evaluate maternal serum thiol/disulphide homeostasis in pregnancies complicated by fetal distress (FD). A total of 100 patients beyond the 34th week of pregnancy were included in this study, and they were divided into two groups. The study group included 50 patients who had been diagnosed with FD; the control group was composed of 50 patients who had shown no signs of FD and who had undergone an elective (previous) caesarean section (CS). The native thiol, total thiol and native thiol/total thiol (%) concentrations were lower in Group 1 patients than Group 2 patients (p < .001). The disulphide, disulphide/native thiol (%) and disulphide/total thiol (%) concentrations were higher in Group 1 patients than Group 2 patients (p < .001). This study suggests that maternal thiol/disulphide homeostasis is impaired in pregnancies complicated by FD.IMPACT STATEMENTWhat is already known about this subject? Oxidative stress (OS) has previously been investigated in FD. This study reports for the first time a new novel and automatic measurement method.What do the results of this study add? This study shows that the thiol balance shifts in the direction of disulphide in the cases of FD.What are the implications of these findings for clinical practice and further research? Thiol balance can be used for the timely diagnosis of FD.

Maternal serum endocan concentrations are elevated in patients with preterm premature rupture of membranes

Objectives To evaluate the maternal serum endocan levels in pregnant women complicated by preterm premature rupture of membranes (PPROM) and to compare the results with healthy pregnancies. Methods This cohort study included 31 pregnant women with PPROM and 34 gestational age-matched healthy subjects in the third trimester of pregnancy. The blood for analysis was obtained on the day of diagnosis and serum endocan levels were measured using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. The pregnant women were observed until the delivery and perinatal data were noted. Results No significant differences regarding maternal age, body mass index, gravidity, parity and gestational age at sampling were observed (P > 0.05). Mean serum endocan level was significantly higher in the PPROM group than in healthy controls (1490 ± 632 pg/mL vs. 972 ± 586 pg/mL, respectively; P: 0.001). Serum endocan concentration was positively correlated with C-reactive protein (CRP) (r = 0.754, P < 0.001) and white blood cells count (WBC) (r = 0.712, P:0.001). The receiver operating characteristic (ROC) curve analysis showed that endocan with a cut-off point of 1198 ng/dL indicated women with PPROM with sensitivity of 64.5% and specificity of 35.1% (area under curve 0.731, confidence interval 0.61-0.85). Conclusion Serum endocan level was significantly elevated in the PPROM patients than in healthy controls. The endocan level may be a useful indicator of endothelial dysfunction/inflammation in PPROM cases.