Evaluation of serum calcium levels in pre-eclampsia

Background: Pre-eclampsia is the most common medical

complication of pregnancy associated with increased maternal and

infant mortality and morbidity. Reduced serum calcium level are

found associated with elevated blood pressure in preeclampsia.

Objectives: To evaluate serum calcium level in preeclamptic

women.

`Methods: This cross sectional study was carried out in among

50 pre-eclamptic patients, aged 20 to 40 years, and gestational

age ranges from 20 to 40 weeks and 50 age and gestational age

matched normotensive pregnant women having no proteinuria.

Serum calcium was measured by Colorimetric method.

Results: The mean age and mean gestational age of pre-eclampsia

was not significantly different from those of normotensive pregnant

women (p=0.203 and p=0.251 respectively). The mean body mass

indexes of the test patients were significantly different from those

of normotensive pregnant women (p<0.001). The mean serum

calcium level was 7.27 ± 3.01 mg/ dl in pre–eclampsia and 7.25

± 2.59 mg/dl in normal pregnant women; did not differ significantly

between the subjects of pre–eclampsia and normal pregnant

women (p=0.963). Conclusion: Serum calcium has no association

in occurrence of pre–eclampsia. Pre-eclampsia is defined as

gestational hypertension of at least 140/90mmHg on two separate

occasions ≥ 4 hours apart accompanied by significant proteinuria

of at least 300mg in a 24-hour collection of urine, arising de novo

after the 20th week of gestation in a previously normotensive and

non-proteinuric woman resolving completely by the 6th postpartum

week . The pregnant woman’s body provides daily doses of 50

to 330mg of calcium to support the developing foetal skeleton.

This high foetal demand for calcium is facilitated by profound

physiological interaction between mother and fetus . This additional

calcium is normally provided by an increase in maternal intestinal

calcium absorption. There may not be a necessary increase in

dietary calcium intake. Several studies have linked calcium to the

aetiopathogenesis and prevention of preeclampsia, however, the

precise mechanism involved is unclear. Normal Serum total calcium

is 2.2- 2.6mmol/L(8.6-10.3mg/dl). Thus values less than 2.2mmol/L

(< 600 mg/day, corresponding to less than two dairy serving per day)

may harm by causing vasoconstriction, either through increasing

magnesium levels or stimulating release of parathyroid hormone

or renin, thereby increasing vascular smooth muscle intracellular

calcium. Some studies have shown that changes in the level of

serum trace elements in pre-eclamptic patients may be implicated

in its pathogenesis.

There is paucity of studies on the relationship between serum

calcium and pre-eclampsia in Nigeria and none from Imo State.

Thus, this study will give a baseline of the relationship between

serum calcium and pre-eclampsia in pregnant women carrying

singleton fetus in Imo State.