Serum magnesium at 18-20 weeks of gestation: can it be a predictor of gestational hypertension and fetomaternal outcome?

Sasikala Kathiresan, Agalya Angelina Sanjevrajah, Jeyashree Kathiresan


Background: Hypertensive disorders of pregnancy (HDP) is a major cause of maternal, fetal morbidity and mortality complicating 10% of all gestations. As effective treatments are very limited, prediction of HDP occurrence is most importance. Though many biomarkers have shown relationship with HDP, serum magnesium (Mg) has shown better predictor as involved in maintaining vascular contractility, tone. This study is intended to analyse incidence of GHT and fetomaternal outcome in pregnant women with normal and low serum magnesium level measured at mid trimester (18-20 weeks).

Methods: A total of 105 consecutive singleton pregnant women in between 18-20 weeks of gestation attending OBG outpatient department were enrolled. After obtaining the informed consent, structured proforma was used to collect demographic, clinical details. Serum magnesium was measured by the colorimetric method and study participants were divided into two groups based on Mg cut off 1.5 mg/dl and followed up throughout pregnancy for fetomaternal outcome.

Results: This study results revealed that 35.2% (37/105) pregnant women had serum Mg level < 1.5 mg/dl and mean value of Mg of all participant is 1.7 mg/dl, just above the lower limit. During follow-up of these two groups, statistically significant correlation between serum Mg levels (< 1.5 mg/dl) with GHT (8/12) occurrence and pre term birth was found. Other fetomaternal outcome not had significant correlation.

Conclusions: As per the findings, serum Mg concentration measurement in between 18-20 weeks can be considered as a one of the predictors for subsequent occurrence of maternal outcome of GHT and fetal outcome of pre-term birth.


Fetomaternal outcome, Gestational hypertension, Predictor, Serum magnesium

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Lai C, Coulter SA, Woodruff A. Hypertension and pregnancy. Tex Heart Inst J. 2017;44(5):350-1.

Magee LA, Helewa M, Rey E, Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy. J Obstet Gynaecol Can JOGC J Obstet Gynecol Can. 2008;30(3 Suppl):S1-2.

Khumanthem PD, Chanam MS, Samjetshabam RD. Maternal mortality and its causes in a tertiary center. J Obstet Gynaecol India. 2012;62(2):168-71.

You F, Huo K, Wang R, Xu D, Deng J, Wei Y, et al. Maternal mortality in Henan Province, China: changes between 1996 and 2009. PloS One. 2012;7(10):e47153.

Upadya M, Rao ST. Hypertensive disorders in pregnancy. Indian J Anaesth. 2018;62(9):675-81.

Mehta B, Kumar V, Chawla S, Sachdeva S, Mahopatra D. Hypertension in pregnancy: a community-based study. Indian J Community Med Off Publ Indian Assoc Prev Soc Med. 2015;40(4):273-8.

Umesawa M, Kobashi G. Epidemiology of hypertensive disorders in pregnancy: prevalence, risk factors, predictors and prognosis. Hypertens Res Off J Jpn Soc Hypertens. 2017;40(3):213-20.

Lo JO, Mission JF, Caughey AB. Hypertensive disease of pregnancy and maternal mortality. Curr Opin Obstet Gynecol. 2013;25(2):124-32.

Backes CH, Markham K, Moorehead P, Cordero L, Nankervis CA, Giannone PJ. Maternal preeclampsia and neonatal outcomes. J Preg. 2011:Article ID 214365.

Takaya J, Yamato F, Kaneko K. Possible relationship between low birth weight and magnesium status: from the standpoint of “fetal origin” hypothesis. Magnes Res. 2006;19(1):63-9.

Tavana Z, Hosseinmirzaei S. Comparison of maternal serum magnesium level in pre-eclampsia and normal pregnant women. Iran Red Crescent Med J. 2013;15(12):2.

Enaruna NO, Ande ABA, Okpere EE. Clinical significance of low serum magnesium in pregnant women attending the University of Benin Teaching Hospital. Niger J Clin Pract. 2013;16(4):448.

Kintiraki E, Papakatsika S, Kotronis G, Goulis DG, Kotsis V. Pregnancy-Induced hypertension. Horm Athens Greece. 2015;14(2):211-23.

Baumann MU, Bersinger NA, Surbek DV. Serum markers for predicting pre-eclampsia. Mol Aspects Med. 2007;28(2):227-44.

Luo Q, Han X. Second-trimester maternal serum markers in the prediction of preeclampsia. J Perinat Med. 2017;45(7):809-16.

Monte S. Biochemical markers for prediction of preclampsia: review of the literature. J Prenat Med. 2011;5(3):69-77.

Kanagal DV, Rajesh A, Rao K, Devi UH, Shetty H, Kumari S, et al. Levels of serum calcium and magnesium in pre-eclamptic and normal pregnancy: a study from coastal India. J Clin Diagn Res JCDR. 2014;8(7):OC01-4.

Darkwa EO, Antwi-Boasiako C, Djagbletey R, Owoo C, Obed S, Sottie D. Serum magnesium and calcium in preeclampsia: a comparative study at the Korle-Bu Teaching Hospital, Ghana. Integr Blood Press Control. 2017;10:9.

Wolf FI, Trapani V, Simonacci M, Ferré S, Maier JAM. Magnesium deficiency and endothelial dysfunction: is oxidative stress involved? Magnes Res. 2008;21(1):58-64.

Kass L, Weekes J, Carpenter L. Effect of magnesium supplementation on blood pressure: a meta-analysis. Eur J Clin Nutr. 2012;66(4):411-8.

Venu L, Padmavathi IJN, Kishore YD, Bhanu NV, Rao KR, Sainath PB, et al. Long-term effects of maternal magnesium restriction on adiposity and insulin resistance in rat pups. Obes Silver Spring Md. 2008;16(6):1270-6.

Rosner JY, Gupta M, McGill M, Xue X, Chatterjee PK, Yoshida-Hay M, et al. Magnesium deficiency during pregnancy in mice impairs placental size and function. Placenta. 2016;39:87-93.

Morton A. Hypomagnesaemia and pregnancy. Obstet Med. 2018;11(2):67-72.

Pathak P, Kapoor SK, Kapil U, Dwivedi SN. Serum magnesium level among pregnant women in a rural community of Haryana State, India. Eur J Clin Nutr. 2003;57(11):1504-6.

Shahid AR, Hosna AU, Tahmina HZ. Hypomagnesaemia in pregnancy: a predictor of preterm labour. J Dhaka Med Coll. 2010;19(1):51-7.