Placental Release of Corticotrophin-releasing Hormone Across the Umbilical Circulation of the Human Newborn

Abstract This study attempted to determine the placental release of corticotrophin-releasing hormone (CRH) into the umbilical circulation, and the factors which affect it, by measuring venous and arterial levels for CRH across the umbilical circulation in labouring as well as non-labouring elective caesarean section patients. The relationship with measures of fetal oxygenation and acid-base status at birth was investigated also. Forty-eight patients were studied (term labour n=30, term elective caesarean section n=12, and preterm labour n=6) with blood sampling from a clamped segment of cord after delivery of the fetus and from the cord at its insertion into the placenta after delivery of the placenta, with subsequent measurement of blood gases, pH, base excess, and CRH. For all patients, mean plasma CRH levels in the umbilical and placental vein (115±13 and 145±18 pg/ml) were higher than those from the corresponding artery (85±7 and 102±8 pg/ml, P