Published: 2016-12-15

eterminants of seizure occurrence in preeclampsia before commencing and during treatment with magnesium sulphate

John O. Imaralu, Olusegun O. Badejoko, Olabisi M. Loto, John C. Ihongbe


Background: Eclampsia is considered as a consequence of severe preeclampsia, with magnesium sulphate regarded as gold standard in seizure treatment and prophylaxis. Convulsions have however been noted when criteria for severe preeclampsia were not met and in patients undergoing treatment with magnesium sulphate.

Methods: A secondary analysis of data obtained from a prospective cross sectional study, involving assessment of clinical and biochemical markers of preeclampsia including magnesium in 75 patients with severe preeclampsia who were given magnesium sulphate using the Pritchard regimen.

Results: Headache (p = 0.002), vomiting (p = 0.005) and prior occurrence of seizures before presentation (p = 0.001), were significant risk factors for occurrence of convulsions. In addition, serum magnesium levels were significantly lower (1.61±0.32 mg/dL) among patients who had seizures than in those who did not (2.01±0.25 mg/dL), (p<0.001). Systolic blood pressure (p = 0.22), diastolic blood pressure (p = 0.29), mean arterial blood pressure (p = 0.17) and proteinuria (p = 0.18) however did not determine the occurrence of seizures. Only 3/49 (6.1%) of the patients with severe hypertension (MAP≥125 mmHg) fitted, compared to 6/26 (23.1%) with mild hypertension (MAP<125mmHg) who convulsed (p = 0.04). Convulsion during treatment with MgS04 was associated with significantly lower levels of serum magnesium (4.04±0.5 mg/dL), than 4.63±0.5 mg/dL observed among patients with severe preeclampsia who did not convulse (p = 0.04).

Conclusions: Headache, vomiting, prior convulsion and low serum magnesium levels preceded the occurrence of fits before treatment while, prior convulsion and low serum magnesium level consistently preceded the occurrence of fits during treatment of preeclampsia with magnesium sulphate.


Eclampsia, Prediction, Seizures, Preeclampsia, Magnesium sulphate

Full Text:



Report of the National high blood pressure education program working group on high blood pressure in pregnancy. Am J Obstet Gynecol. 2000;183:S1-22.

Steegers EA, von Dadelszen P, Duvekot JJ, Pijnenborg R. Preeclampsia. The Lancet. 2010;376:631-44.

Sibai B, Dekker G, Kupferminc M. Preeclampsia. The Lancet. 2005;365(9461):785-99.

Langer A, Villar J, Tell K, Kim T, Kennedy S. Reducing eclampsia-related deaths a call to action. Lancet. 2008;371(9614):705-6.

Waugh JJ, Clark TJ, Divakaran TG, Khan KS, Kilby MD. Accuracy of urinalysis dipstick technique in predicting significant proteinuria in pregnancy. Obstet Gynaecol. 2004:103:769-77.

Ozumba BC, Ibe AI. Eclampsia in Enugu, eastern Nigeria. Acta Obstet Gynecol Scand. 1993;72(3):189-92.

Redman CING, Sacks GP, Sargent IL. Preeclampsia NA excessive maternal inflammatory response to pregnancy. Am J Obstet Gynecol. 1999;180(2):499- 506.

James JL, Whitley GS, Cartwright JE. Preeclampsia: fitting together the placental, immune and cardiovascular pieces. J Patho. 2010;221(4):363-78.

Koch S, Rabinstein A, Falcone S, Forteza A. Diffusion-weighted imaging shows cytotoxic and vasogenic edema in eclampsia. Am J Neurorad. 2001;22:1068-70.

Kanki T, Tsukimori K, Mihara F, Nakano H. Diffusion-weighted images and vasogenic edema in eclampsia. Obstet Gynecol. 1999;93:821-3.

Fletcher JJ, Kramer AH, Bleck TP, Solenski NJ. Overlapping features of eclampsia and postpartum angiopathy. Neurocrit Care. 2009;11(2):199-209.

Shah AK, Rajamani K, Whitty JE. Eclampsia: a neurological perspective. J Neurol Sci. 2008;271:158-67.

Thomas SV. Neurological aspects of eclampsia. J Neurol Sci. 1998;155:37-43.

MacKay AP, Berg CJ, Atrash HK. Pregnancy-related mortality from preeclampsia and eclampsia. Obstet Gynecol. 2001;97(4):533-8.

Duley L. The global impact of preeclampsia and eclampsia. Semin Perinatol. 2009;33(3):130-7.

The Magpie Trial Collaborative Group. Do women with preeclampsia, and their babies, benefit from magnesium sulphate? The Magpie Trial: a randomized placebo-controlled trial. Lancet. 2002;359:1877-90.

Pritchard JA, Cunningham FG, Prichard SA. The Parklands memorial hospital protocol for treatment of eclampsia: evaluation of 245 cases. Am J obstet Gynecol. 1984:84:607-10.

Tong GM, Rude RK. Magnesium deficiency in critical illness. J Intensive Care Med. 2005;20:3-17.

Touyz RM. Role of magnesium in the pathogenesis of hypertension. Mol Aspects Med. 2003;24:107-36.

Idogun ES, Imarengiaye CO, Momoh SM. Extracellular calcium and magnesium in preeclampsia and eclampsia. African J Reprod Health. 2007;11(2):89-94.

Meads CA, Cnossen JS, Meher S, Juarez-Garcia A, ter Riet G, Duley L, et al. Methods of prediction and prevention of preeclampsia: systematic reviews of accuracy and effectiveness literature with economic modeling. Health Technol Assess. 2008;12:3-4.

Sibai BM. Diagnosis, prevention, and management of eclampsia. Obstet Gynecol. 2005;105(2):402-10.

Douglas KA, Redman CWG. Eclampsia in the United Kingdom. BMJ. 1994;309:1395-400.

Katz VL, Farmer R, Kuller JA. Preeclampsia into eclampsia: toward a new paradigm. Am J Obstet Gynecol. 2000;182:1389-96.

Imaralu JO, Olaleye AO, Badejoko OO, Loto OM, Ogunniyi SO. The use of magnesium sulphate

(MgSO4) for seizure prophylaxis: clinical correlates in a Nigerian tertiary hospital. IJMBR. 2015;4:(2).

Preedatham K, Tansupswatdikul P. Serum magnesium level in severe preeclampsia and eclampsia patients, undergoing magnesium sulfate therapy at Chonburi hospital. Thai J Obstetr Gynaecol. 2009;17:190-5.

Phuapradit W, Saropala N, Haruvasin S, Thuvasethakul P. Serum level of magnesium attained in magnesium sulfate therapy for severe preeclampsia. Asia Oceania J Obstet Gynaecol. 1993;19(4):387-90.

Kirkwood BR, Sterne JAC. Essential Medical Statistics, 2nd ed, Blackwell Science Ltd. Massachusetts; 2003:420.

Owolabi AT, Fatusi AO, Kuti O, Adeyemi AB, Faturoti SO, Obiajunwa PO. Maternal complications and outcomes in booked and unbooked Nigerian mothers. Singapore Med J. 2008;49(7):526-31.

Mattar F, Sibai BM. Eclampsia. VIII. Risk factors for maternal morbidity. Am J Obstet Gynecol. 2000;182(2):307-12.

Cooray SD, Edmonds SM, Tong S, Samarasekera SP, Whitehead CL. Characterization of symptoms immediately preceding eclampsia. Obstet Gynecol. 2011;118(5):995-9.

France J, Muganyizi P. Characteristics of symptoms of imminent eclampsia: a case referent study from a tertiary hospital in Tanzania. Open J Obstet Gynecol. 2012;2:311-7.

Knight M. Eclampsia in the United Kingdom 2005. BJOG. 2007;114:1072-8.

Hallak M, Berman RF, Irtenkauf SM, Janusz C, Cotton DB. Magnesium sulfate treatment decreases N-methyl-D-aspartate receptor binding in the rat brain: an auto-radiographic study. J Soc Gynecol Invest. 1994;1:25-30.

Ekele BA, Badung SL. Is serum magnesium estimate necessary in patients with eclampsia on magnesium sulphate? Afr J Reprod Health. 2005;9:128-32.

Dayicioglu V, Sahinoglu Z, Kol E, Kucukbas M. The use of standard dose of magn esium sulphate in prophylaxis os eclamptic seizures; do BMI alterations have any effect on success? Hypetens Pregnancy. 2003:22(3):237-65.

Abbade JF, Costa RA, Martins AM, Borges VT, Ridge MV, Perocalli JC. Zuspans’ scheme versus an

alternative magnesium sulphate scheme; randomized clinical trial of magnesium serum concentrations. Hypertens Pregnancy. 2010;29(1):82-92.