[Parathyroid hormone: perinatal aspects].

Authors have measured parathormone levels in 28 mothers at delivery and their respective newborns at 40-50 hours after birth. They also quantified these levels in umbilical vessels. Control groups was formed by 48 healthy non pregnant women. PTH levels in pregnant women were similar to controls. In umbilical artery these values were higher than in umbilical vein and in both, lower than other groups. Newborns at 40-50 hours after birth showed higher PTH levels than controls and pregnant women at delivery. A positive correlation between the PTH levels of the mother and those of the umbilical vessels is found. PTH levels of the neonate at 40-50 hours after birth correlated with levels of umbilical artery and umbilical vein. They do not observe a hyperparathyroidism at the delivery, although there is a slight decrease in Ca levels. Newborns at 40-50 hours after birth did show an increase in their PTH levels in parallel with hypocalcemia correlation found between PTH levels of the mother and those of the umbilical vessels could suggest a placental transfer for this hormone.