Serum magnesium in healthy pregnant women in a teaching hospital in South-South Nigeria

Abstract

Context: Magnesium plays a crucial role in metabolism especially with respect to carbohydrate, protein and energy syntheses. Its decline in pregnancy has been associated with conditions like preeclampsia and preterm delivery. We assess the prevalence of hypomagnesaemia in our locale and examine the associated maternal characteristics.
Objectives: The primary objective was to determine the level of serum magnesium at which hypomagnesaemia could be diagnosed, while secondary objective was to define maternal characteristics associated with hypomagnesaemia.
Study Design, Setting and Subjects: A pilot study was done to document the mean serum magnesium level for the population of female patients attending UBTH. The main study was a cross-sectional study of healthy antenatal women recruited between 24 and 26 weeks of pregnancy. Serum magnesium estimates were done with samples collected at recruitment. The magnesium levels determined were used to divide the subjects into two groups of hypomagnesaemic and normomagnesaemic patients. Their sociodemographic characteristics were used to generate a database for analysis.
Results: Serum magnesium levels were higher in the non-pregnant subjects than the pregnant women in the pilot study. The prevalence of magnesium deficiency in the main study was 16.25%. Hypomagnesaemia was more likely in teenagers (P=0.00), women of higher parities (P=0.02) and lower social class (P=0.00).
Conclusion: Hypomagnesaemia in pregnancy is common in teenagers, women of high parity and low social class. Magnesium supplementation or consumption of magnesium-rich food is recommended for these groups of women, while discouraging too early, frequent or many deliveries.

Keywords: serum magnesium, pregnant women, south-south Nigeria

Trop J Obstet Gynaecol, 30 (1), April 2013