Reduced Urinary Excretion of Calcium in Pregnancy-Induced Hypertension: Relationship to Renal Prostaglandin Excretion

Abstract

Urinary excretion of calcium, sodium, creatinine, proteins and renal prostaglandins (PGE₂, 6kPGF₁α) and serum levels of calcium, sodium, creatinine and albumin were determined in 10 normotensive pregnant women throughout pregnancy and in 30 normotensive pregnant women (NTP) and 30 women with pregnancy-induced hypertension or preeclampsia (HTP) and intact kidney function in the third trimester in comparison with 13 nonpregnant control subjects (C).

Urinary excretion of calcium was found to be significantly reduced in the HTP group and was correlated with PGE₂ excretion (p < 0.01). A weak correlation was detectable in the NTP group, which, however, as in the HTP and C groups, showed a close correlation between urinary calcium and sodium values (p < 0.05). In the NTP group, there was a significant increase in calcium excretion, which might reasonably be regarded as related to increased renal PG activity.