Neurohumoral and biochemical markers of prolonged second stage of labor

Objective: to study the role of neurohumoral and biochemical changes in the pathogenesis of prolonged second stage of labor.

Material and methods. To achieve the above objective, we examined 35 parturient women with prolonged second stage of labor and 45 parturient women with physiological labor. We studied the levels of progesterone, estradiol, relaxin, serotonin, cholesterol, thiobarbituric acid reactive substances (TBARS), total antioxidant capacity of plasma, products of final protein oxidation, as well as the total concentrations of nitrite and nitrate ions (NOx) in blood plasma.

Results. In the women with prolonged second stage of labor, the levels of estradiol and progesterone were significantly higher than in those with physiological childbirth (p1 = 0.037, p2 = 0.029). The women giving birth by operation had higher estradiol (p = 0.017) and progesterone (p = 0.07) levels than those giving birth physiologically. The level of relaxin was lower in the women with prolonged second period of labor than in those with physiological labor (p = 0.084), especially in the case of operative delivery (p = 0.041), the risk of which increases 4.1 times when the relaxin concentration is less than 36.4 ng/l. Compared to the patients giving physiological childbirth, the patients with prolonged second stage of labor who delivered by cesarean section had significantly higher TBARS levels (p = 0.043). Its concentration > 180.3 μmol/l increases the risk of cesarean section almost by 12 times (p = 0.003).

Conclusion. The hormonal aspect of the pathogenesis of prolonged second stage of labor is characterized by higher concentrations of steroid hormones — estradiol and progesterone, as well as by a lower level of relaxin in plasma. The biochemical aspect of the pathogenesis is represented by an increased concentration of lipid peroxidation products, which can be identified with severe physical fatigue in childbirth. The detected changes can be applied in the complex diagnostics of prolonged second stage of labor.

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