Ravulizumab in Pregnancies Complicated by Severe Hypertensive Disorders

This study is testing whether a drug called ravulizumab — which blocks part of the immune system — can help pregnant women who develop severe high blood pressure complications (such as severe preeclampsia or HELLP syndrome) before 34 weeks of pregnancy. These dangerous conditions can harm both mother and baby. **You may be eligible if...** - You are pregnant and less than 34 weeks along - You have been diagnosed with severe preeclampsia or HELLP syndrome (a serious condition involving high blood pressure, liver problems, and low platelets) **You may NOT be eligible if...** - You have developed a dangerous blood-clotting disorder (DIC) - Your baby is showing signs of distress that require immediate delivery - Your pregnancy is before 23 weeks or a fetal death has occurred - You have certain blood or immune conditions (such as atypical HUS, TTP, or PNH) - You are allergic to ravulizumab - You are unable or unwilling to give informed consent Talk to your doctor to see if this trial is right for you.