Calcium, Parathyroid Hormone and Calcitonin in Normal Pregnancy and Preeclampsia

Abstract

Calcium, parathyroid hormone (PTH) and calcitonin (CT) in serum, and the fractional renal excretion of calcium (FE_Ca) were determined in (1) normal pregnant women, (2) patients with preeclampsia, and (3) normal nonpregnant control subjects. Serum calcium, corrected for individual variation in serum protein, was reduced and FE_Ca increased in the normal pregnant group when compared to the nonpregnant control group. In preeclampsia serum calcium did not differ significantly from the normal pregnant group, but FE_Ca was considerably lower and also reduced below the level in the nonpregnant control group. PTH was slightly lower during normal pregnancy than after delivery, but did not deviate significantly from the nonpregnant control group; in preeclampsia PTH did not deviate significantly from the levels in normal pregnancy. CT was the same in the third trimester of pregnancy in both groups. Changes in serum calcium and FE_Ca were not correlated to PTH or CT. It is concluded that both normal pregnancy and preeclampsia are accompanied by considerable alterations in calcium metabolism, that PTH and CT in both groups are mainly unchanged and at nonpregnant level, and that the increase and decrease in renal calcium excretion in normal pregnancy and preeclampsia, respectively, may be attributed to changes in kidney function.

STUDY OF SERUM CALCIUM, MAGNESIUM & URINE MICROALBUMIN LEVELS IN NORMAL & PRE-ECLAMPTIC GESTATION & TO COMPARE WITH NON-GESTATIONAL VALUE.

“…While other reports have shown that there is increase in serum Ca in pregnant women compared to non-pregnant women. [8] However, it should be noted that this observation was made in the Western (developed) countries where there is sufficient Ca and vitamin D intake during pregnancy since there is a direct linear relationship between dietary intake of Ca and its serum concentration. [9,10] The role of magnesium appears to be associated with its function as an activator of enzymes involved in membrane transport and integrity, and with its relationship to prostaglandins -specifically, the ratio of prostacyclins (vasodilators) and thromboxanes (some of which are vasoconstrictors), which is dramatically altered in the case of low serum magnesium [11].…”

A Prospective Study for the Prediction of Preeclampsia with Urinary Calcium Level

“…Parathyroid hormone (PTH) was lower in preeclampsia due to increased renal calcium absorption, thereby reaching a new steady state of normocalcemia associated with lower PTH [9]. Pedersen et al [10] reported that the fractional excretion of calcium was reduced in the third trimester in preeclamptics as compared with normotensives. Because parathyroid hormones and calcitonin levels were not altered in the patients with preeclampsia, they concluded that the difference in calcium metabolism was not noted to alter the secretion of these hormones.…”

Alterations of plasma calcium and intracellular and membrane calcium in erythrocytes of patients with pre-eclampsia

“…16 However, reports regarding changes in serum total calcium concentration are equivocal, a number of studies found decreased serum levels in normal pregnancy, others reported no difference in serum calcium levels of pre-eclamptic women and healthy pregnant women or non-pregnant controls. [6][7][8][9][10] The controversial reports may be in part due to small numbers of Journal of Human Hypertension patients. A possible beneficial effect of calcium supplementation in pregnancy is also discussed controversially.…”

“…[7][8][9] However, results concerning calcium metabolism in pregnancy are equivocal. 10 The use of calcium supplementation for prevention and treatment of pre-eclampsia is also controversely discussed. Oral calcium supplementation and thus increase of plasma calcium alone seem not to reduce the incidence of the disease.…”