Nitric oxide metabolite levels and assessment of cervical length in the prediction of preterm delivery among women undergoing symptomatic preterm labor

Abstract

Objective: To evaluate the diagnostic accuracy of measuring cervical length (CL) in combination with cervical and plasma nitric oxide metabolite (NOx) levels to identify women undergoing preterm labor (PTL) who will deliver preterm. Methods: A hospital-based prospective cohort study of 730 women undergoing spontaneous PTL between 24 and 33 weeks + 6 days of pregnancy was conducted. Measurement of cervical and plasma NOx levels and ultrasonographic assessment of CL were performed to find the best model to predict preterm delivery (PTD). Optimal cut-off values were calculated by receiver operating characteristic (ROC) curve analysis. Logistic regression analysis and rank correlation tests were also performed. Results: CL of 15 mm or less, cervical NOx levels greater than 87.6 μmol/L, and plasma NOx levels greater than 123 μmol/L (P b 0.0001) were the only factors significantly associated with PTD within 7 days of sampling. This combined model provided high diagnostic accuracy (sensitivity 80.0%; specificity 99.2%). Both cervical and plasma NOx levels were negatively correlated with CL (r = − 0.453, P b 0.0001 and r = − 0.362, P b 0.0001, respectively). Conclusion: Combined measurement of CL and levels of cervical and plasma NOx could help identify women undergoing symptomatic PTL who are at increased risk of PTD.

Maternal plasma nitric oxide metabolites and cervical length assessment in predicting the tocolytic therapy in preterm labor in Isfahan

“…In other studies, there was variable cutoff. In comparison with our assessment (NOx ≤31 [μmol/L]), some studies have reported the higher amount of NO (NOx ≤ 123 [μmol/l]),[13] while other probations have stated the lower NO level compared with our findings. [18] We believe that the fluctuation of NOx level might be related to our different population nature or small sample size, and we encounter with limiting external validation of the result, and more investigations are needed to evaluate the level of NO in bigger population.…”

“…Despite finding a positive correlation between NOx level and CL in PTL, other findings reported the opposite relation. [13] The survey performed by Duckitt and Thornton demonstrated that using magnesium sulfate, which causes an elevated level of NO, had no significant effect of PTL. [25] None of the trials addressed the alteration in cervical ripening or prolonged delivery.…”

“…Those who have contraindications to medications such as tocolysis (fetal asphyxia, fetal growth restriction, and placental problems, such as a placenta previa or abruption) were also excluded from the study (ten females have been excluded from the study because of some problems). [13] In addition, the study was approved by the Isfahan University of Medical Sciences’ Ethical Committee with the code of 392348.…”

“…[12] The use of tocolytic agents in contemporary obstetric practice should be customized based on the available evidences of efficacy and fetomaternal safety, gestational age, maternal conditions, and drugs’ potential complications. [13] Magnesium sulfate is one of the tocolytic agents which is commonly used for tocolytic therapy, and despite maternal side effects, its usage in women at risk of preterm birth helps to protect the child's brain, to reduce the rates of cerebral palsy, and to improve long-term neonatal outcomes. [1011121314]…”

“…[13] Magnesium sulfate is one of the tocolytic agents which is commonly used for tocolytic therapy, and despite maternal side effects, its usage in women at risk of preterm birth helps to protect the child's brain, to reduce the rates of cerebral palsy, and to improve long-term neonatal outcomes. [1011121314]…”