Calciuric levels in pregnant women with high blood pressure

Abstract

OBJECTIVE: Arterial hypertension is one of the main causes of maternal and perinatal
morbimortality in Southern Brazil. Most studies concerning urinary calcium excretion
during pregnancy have found lower levels of calcium excretion in patients with
preeclampsia compared with normotensive pregnant patients and with pregnant patients
with preexisting chronic hypertension and without preeclampsia. The objective of this
study was to evaluate urinary calcium excretion in women with hypertensive disorders
during pregnancy.
MATERIALS AND METHODS: All pregnant women who were hospitalized at the Obstetric
Center of the Hospital de Clínicas Teaching Hospital for increased blood pressure and
between December 1998 and September 1999, were submitted to a protocol for collection
of demographic data, blood pressure data, and laboratory exams data (proteinuria;
calciuria; and creatinuria from 24-h urine samples; proteinuria/creatinuria ratio; and
serum uric acid). We determined hypocalciuria for urinary calcium excretion < 100 mg/
24h and significant proteinuria for protein excretion > 300 mg/24h.
RESULTS: The 71 patients studied presented averages of 26 years of age, 34 weeks of
gestation, and mean blood pressure of 151/98 mmHg. As to clinical development,
35.2% of patients were diagnosed with preeclampsia, 8.5% with chronic hypertension,
2.8% with eclampsia, 15.5% with preeclampsia over essential hypertension, 2.8% with
HELLP syndrome, and 35.2% with transient hypertension. Patients with preeclampsia
showed 24-h calciuria significantly lower than that of patients with transient increase in
blood pressure. There was no significant difference in 24-h calciuria from pregnant
women with chronic hypertension and from women with preeclampsia.
RESULTS: These results suggest that simple mensuration of urinary calcium excretion
can help diagnose hypertensive disorders during pregnancy.