Reitz R E, Daane T A, Woods J R, Weinstein R L
Obstet Gynecol. 1977 Dec;50(6):701-5.
The ability to measure directly human parathyroid hormone (hPTH) and ionized calcium (Ca++) is of fundamental importance in understanding their interrelation in pregnancy and the newborn. hPTH and Ca++ progressively increase throughout pregnancy. Since Ca++ is the direct determinant of hPTH levels, a different "set point" appears to be operative throughout pregnancy. The newborn infant, on the other hand, has higher serum Ca++ levels than its mother, and the infant's plasma hPTH is suppressed to undetectable or low levels. Ca++, total serum Ca, magnesium, and phosphorus are all significantly elevated in the serum of the mother at delivery. An active transport mechanism of all these minerals appears to be operative and lowers the maternal serum levels at the termination of labor in relation to serum levels in the third trimester of pregnancy.
直接测量人甲状旁腺激素（hPTH）和离子钙（Ca++）的能力对于理解它们在妊娠和新生儿中的相互关系至关重要。在整个孕期，hPTH和Ca++会逐渐升高。由于Ca++是hPTH水平的直接决定因素，在整个孕期似乎存在不同的“设定点”。另一方面，新生儿的血清Ca++水平高于其母亲，且婴儿血浆中的hPTH被抑制至无法检测或低水平。分娩时母亲血清中的Ca++、总血清钙、镁和磷均显著升高。所有这些矿物质的主动转运机制似乎都在起作用，并且相对于妊娠晚期的血清水平，在分娩结束时会降低母亲的血清水平。
