Serum Magnesium Concentration in Magnesium Sulfate Therapy for Severe Preeclampsia

This observational, longitudinal, prospective case-series aims to assess serum magnesium concentrations at specific times in pregnant women treated with magnesium sulfate for pre-eclampsia with severe features. Pregnant women aged minimum 18 who are admitted to My Duc Hospital with severe pre-eclampsia, as defined by the American College of Obstetricians and Gynecologists (ACOG) diagnosis criteria, will be indicated for therapy with magnesium sulfate. Only those who give written informed consent will be included in the study. According to the ACOG criteria, pre-eclampsia is considered severe if present with any of the following features : systolic blood pressure ≥160 mmHg and/or diastolic blood pressure ≥110 mmHg, thrombocytopenia (\<100,000/mm3) abnormal liver function (increase in transaminases to twice the normal value or pain in the upper right quadrant/epigastrium that is unresponsive to medication), abnormal renal function (creatinine \>1.1 mg/dl or twice normal values), acute pulmonary edema and/or new cerebral and/or visual symptoms. Exclusion criteria includes impaired renal function (eGFR \< 60 mL/min/ 1,73 m2 or oliguria ), known hypersensitivity to the drug, severe myasthenia, atrioventricular block or a diminished level of consciousness. All patients will be given the standard loading dose of 4.5 grams of magnesium sulfate administered over 20 minutes, followed by a maintenance dose of magnesium sulfate at an infusion rate of 1.5g/h, in compliance with My Duc Hospital's guidelines. Maternal blood samples will be obtained for serum magnesium and creatinine concentrations at baseline prior to magnesium sulfate administration; at 30 min, 1 hour, 2 hours, 4 hours and every 6 hours until discontinuation of magnesium sulfate therapy. Antihypertensive medications can be given according to My Duc Hospital's guidelines. Patients can choose to withdraw from the study at any point without affect on the course of treatment. Investigators can also offer patients to opt out of the study for medical emergencies. Magnesium sulfate therapy will be discontinued if there is any sign of magnesium toxicity, or the patient has been stable for 24 hours of treatment without any severe hypertensive episode or convulsion. All patients will be followed up until delivery and both mother and neonate are discharged to record obstetric and neonatal outcomes.