Preterm Preeclampsia Study (PRO00002975)

ATryn® is a form of human antithrombin, which your body uses to keep blood clots from forming. ATryn® is currently approved by the FDA for the prevention of perio-operative (time period around surgery) and peri-partum (time period around childbirth) formation of blood clots in patients who have an inherited disorder that causes them not to produce enough antithrombin. Women who develop preterm preeclampsia generally have lower than normal antithrombin levels. Therefore, one theory for the study is that administration of ATryn® could help improve the condition of preeclampsia and allow pregnancy to continue longer. If you agree to participate, in addition to the standard of care treatment provided by your physician, you will be randomly assigned to receive either ATryn® or placebo via intravenous infusion (through a vein). If you are assigned to receive ATryn®, you will receive an initial “loading dose” containing 250 milligrams of ATryn® mixed with normal saline, and will be given over 15 minutes to allow the ATryn® to get to a certain level in your blood. After the loading dose is complete, a continuous infusion of ATryn® mixed with normal saline will be started. You will receive a total of 2000 mg of ATryn® per day until your baby reaches gestational age of 34 weeks, or until a decision has been made by your doctor to deliver your baby. If you are assigned to receive placebo (normal saline - an inactive salt solution), you will receive an initial loading dose over 15 minutes and will be immediately followed with a continuous infusion that will go until your baby reaches gestational age of 34 weeks or until a decision has been made by your doctor to deliver your baby. The volume of normal saline will be the same as it would be for the study group receiving ATryn®. This is a double-blind study, which means that neither you nor your study doctor will know to which group you have been assigned. Once you sign the informed consent, you will be screened to determine if you are eligible to participate. Screening will consist of: medical and obstetric history; collection of demographic information; review of medical records and determination of due date; review of current medications being taken; physical examination; measurement of height and weight; vital signs will be taken; and blood and urine will be collected to see how your body is functioning. Once you have been randomized the following will be done: you receive treatment with ATryn® or placebo; your vital signs will be checked twice a day; blood samples will be taken to monitor your health; the medications used/taken during the study will be checked; and you and your unborn baby will be monitored as you normally would if you were not participating in the study. Immediately after delivery of your baby, the following assessments will be performed on your baby: APGAR score (standard test performed after birth to help a physician assess how well the baby is doing); measurement of your baby’s weight, length, and the distance around his or her head; collection of core blood (if available) to measure the level of antithrombin activity in the blood; record information about specific problems related to premature birth or any other serious health problems; and record demographics about your baby including gender, race and ethnicity. You will be followed for 4-6 weeks after delivery.