Magnesium Sulfate in Obese Preeclamptics

Study Overview
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Brief Summary
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The purpose of this study is to learn how medications participant will receive in the course of their delivery are metabolized (broken down by the body). The investigators hope to learn more about the way drugs are metabolized by pregnant women, and how those drugs are distributed in the blood and body compartments and cleared in the urine, and how maternal body weight affects the metabolism. With this information the investigators will be able to develop a treatment regimen considering factors in the body that affect magnesium levels so that the investigators can improve treatment of pregnant women. The goal of the study is to understand how different dosing of magnesium sulfate affects blood levels of the magnesium in larger women.

Detailed Description
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The purpose of this study is to learn how medications participant will receive in the course of their delivery are metabolized (broken down by the body). The investigators hope to learn more about the way drugs are metabolized by pregnant women, and how those drugs are distributed in the blood and body compartments and cleared in the urine, and how maternal body weight affects the metabolism. With this information the investigators will be able to develop a treatment regimen considering factors in the body that affect magnesium levels so that the investigators can improve treatment of pregnant women. The goal of the study is to understand how different dosing of magnesium sulfate affects blood levels of the magnesium in larger women. Magnesium sulfate is generally given to patients to protect the mother against seizures in the case of preeclampsia. Different hospitals in the United States use different doses of magnesium sulfate. Participants will receive one of two accepted doses of magnesium sulfate for preeclampsia. The dose is usually 4g - 6g at the start, with another dose of 2-3 g every hour until 24 hours after delivery. Participants will be assigned to either a dose of 4 g at the start, followed by 1g every hour; or a dose of 6 g at the start, followed by 2g every hour until treatment for preeclampsia is complete. Participants will receive magnesium sulfate in the course of their normal clinical care whether or not they participate in this study.

Official Title
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Randomized Trial of Magnesium Sulfate in Obese Preeclamptic Women

Conditions
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Preeclampsia

Intervention / Treatment
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* Drug: Magnesium sulfate 4g loading dose, 1g/hr infusion
* Drug: Magnesium sulfate 6g loading dose, 2g/hr infusion


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pregnant women who are ages 18-45 32-42 weeks' pregnant Prescribed magnesium sulfate for preeclampsia BMI ≥35 kg/m2 Exclusion Criteria: Pregnant women < 32 weeks' pregnant Women who are on dialysis

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: MgSO4 4g load, 1g/hr infusion<br>Once their obstetrician prescribes magnesium sulfate, participant will be assigned by 50/50 chance to one of two treatment regimens. Participant will be assigned to either a dose of 4 g at the start, followed by 1g every hour; or a dose of 6 g at the start, followed by 2g every hour until treatment for preeclampsia is complete. | Drug: Magnesium sulfate 4g loading dose, 1g/hr infusion<br> <br> |
| Experimental: MgSO4 6g load, 2g/hr infusion<br>Once their obstetrician prescribes magnesium sulfate, participant will be assigned by 50/50 chance to one of two treatment regimens. Participant will be assigned to either a dose of 4 g at the start, followed by 1g every hour; or a dose of 6 g at the start, followed by 2g every hour until treatment for preeclampsia is complete. | Drug: Magnesium sulfate 6g loading dose, 2g/hr infusion<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maternal Serum Magnesium Level at 4 Hours After Administration | magnesium level in mg/dL | 4 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maternal Serum Magnesium Level at Time of Delivery | magnesium level in mg/dL | Within 20 minutes of delivery | 
| Maternal Side Effects | Presence or absence of the following: flushing, lethargy, palpitations, pain at IV site, respiratory depression | 4 hours |