Abstract:
Background: Hypertensive disorders of pregnancy are important causes of morbidity and mortality. The levels of calcium
(Ca2+) and magnesium (Mg2+) in pregnancy may implicate their possible role in pregnancy-induced hypertension. This
study assessed serum Ca2+ and Mg2+ levels in women with PIH (pregnancy-induced hypertension) and PE (pre-eclampsia),
compared to that in normal pregnancy.
Methods: This case–control study was conducted on 380 pregnant women (≥20 weeks gestation) receiving antenatal
care at three hospitals in the Cape Coast metropolis, Ghana. This comprised 120 women with PIH, 100 women with PE
and 160 healthy, age-matched pregnant women (controls). Demographic, anthropometric, clinical and obstetric data were
gathered using an interview-based questionnaire. Venous blood samples were drawn for the estimation of calcium and
magnesium.
Results: Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were significantly raised in women with
PIH (p < 0.0001) and PE (p < 0.0001). Women with hypertensive disorders (PE and PIH) had significantly lower
serum calcium and magnesium levels than those in the control group (p < 0.0001 each). Of those with PIH, SBP
correlated positively with BMI (r = 0.575, p < 0.01) and Ca2+ correlated positively with Mg2+ (r = 0.494, p < 0.01). This was
similar amongst the PE group for SBP and BMI as well as for Ca2+and Mg2+ but was not significant. Multivariate analysis
showed that women aged ≥40 years were at a significant risk of developing PIH (OR = 2.14, p = 0.000).
Conclusion: In this study population, serum calcium and magnesium levels are lower in PIH and PE than in normal
pregnancy. Mineral supplementation during the antenatal period may influence significantly, the occurrence of
hypertensive disorders in pregnancy
