the purpose of this study is to compare Intravenous infusion of Labetalol versus Magnesium Sulfate on Cerebral Hemodynamics of Severe Preeclampsia Patients using Transcranial Doppler

after being informed about the study and potential risks. All patients giving written consent will be randomized by double blind manner into 2 groups each one containing 30 patients , (Group M) : will be given intravenous infusion of magnesium sulfate at a dose of 4 gm intravenously over 20 min as a loading dose then MgSO4 intravenous infusion is continued at a rate of 1 gm/h for 24 h or until obtain and stabilize the targeted blood pressure..

(Group L) : The patients will be given intravenous infusion of labetalol (Trandate™,) available in 20 ml ampoules containing 100mg labetalol (5mg/ml). Starting the infusion with 20mg/h and then titrate to obtain and stabilize the targeted blood pressure by adjusting the infusion as required every 15 - 30min to a maximum dose of 160mg/hr.

Inclusion Criteria:

• acceptance
• 21 to 45 years old.
• mass index ≤ 35 kg/m2.
• Singleton Pregnant female complicated with severe preeclampsia
• Systolic blood pressure ≥ 160 mmHg or diastolic blood pressure ≥ 110 mmHg on two occasions at least 4 hours apart
• Thrombocytopenia (platelet count less than 100,000 )
• Impaired liver function indicated by elevated liver enzymes (to twice the upper limit normal concentration), and severe persistent right upper quadrant or epigastric pain not responding to medications and not explained by another diagnosis.
• Renal insufficiency (serum creatinine concentration more than 1.1 mg/dL or doubling of the serum creatinine concentration in the absence of other renal disease)
• Pulmonary edema
• New-onset headache unresponsive to medications and not accounted for by alternative diagnoses
• Visual disturbances.

Exclusion Criteria:

• Preexisting heart disease
• Known pulmonary disorders.
• Inadequate temporal window.
• Atrial fibrillation and any rhythm abnormality.
• History of allergy or contraindications to either magnesium sulfate or labetolol.
• Exposure to any of the study medications within 24 hours of enrollment.

Singleton Pregnant female complicated with severe preeclampsia