Objective: The purpose of this study was to examine the levels of hormones in umbilical vein blood that affect the neonatal respiratory function in cases of placenta previa and to evaluate the impact of warning bleeding on the hormone levels and neonatal respiratory outcomes such as respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN).
Methods: We analyzed data obtained from 33 placenta previa cases without fetal or maternal complications at 36-38 weeks of gestation. We measured the levels of hormones such as cortisol, arginine vasopressin, epinephrine and norepinephrine in umbilical vein blood using ELISA.
Results: Warning bleeding was found to be a significant factor protecting against neonatal RDS/TTN (p = 0.049). The cortisol levels in the umbilical vein were significantly higher in the cases of previa with warning bleeding than in those without warning bleeding (p = 0.020) and significantly higher in the no RDS/TTN cases than in the RDS/TTN cases (p = 0.040).
Conclusions: Warning bleeding increases the cortisol level in cases of placenta previa. We suggest that genital bleeding may induce stress for both the mother and fetus, resulting in increased cortisol production, thus functioning as a protective factor against neonatal respiratory disorders.
Keywords: Arginine vasopressin; epinephrine; norepinephrine; respiratory distress syndrome; transient tachypnea of the newborn; umbilical vein.