[Changes in serum parathyroid hormone levels during pregnancy]

Abstract

As pregnancy poses a significant challenge to maternal calcium homeostasis, it is interesting to investigate a change in serum parathyroid hormone (PTH) level throughout pregnancy. PTH metabolism in pregnancy has not been clearly defined. We have made an attempt to evaluate changes in serum intact PTH level during pregnancy. Compared with nonpregnant women, serum intact PTH concentrations were decreased significantly in pregnant women during the first and the second trimester, but not during the third trimester. Nephrogenous cyclic AMP excretion, index of parathyroid function has been reported to be decreased in pregnant women during the first and second trimester, but to be in normal range in pregnant women during third trimester. Our finding consisted with these facts.