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
`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.