\--- Why Is This Study Being Done? Women who have preeclampsia during pregnancy face a much higher risk of heart disease later in life. Preeclampsia is a serious pregnancy condition that causes high blood pressure and damages blood vessels. Even after the baby is born, the blood vessels do not fully heal on their own, which can lead to heart problems/cardiovascular years later. This study tests whether a new treatment called exosomes can help repair damaged blood vessels in women who had preeclampsia. Exosomes are tiny particles that come from stem cells and contain healing substances that may help blood vessels work better. \--- What Will Happen in This Study? This study will include 80 women who recently gave birth and had preeclampsia during their pregnancy. Half of the women will receive the exosome treatment through an IV, and half will receive a placebo (a substance with no active treatment). \--- What Will Participants Need to Do? Participants will: * Have blood tests and other health checks * Receive one treatment through an IV * Return for follow-up visits at 1 week after treatment * Have tests to check how well their blood vessels are working Who Can Join This Study? Women who: * Recently gave birth (within 1-2 weeks) * Had preeclampsia during their last pregnancy * Are healthy enough to participate * Can give permission to join the study What Are the Possible Benefits and Risks? The treatment may help repair blood vessel damage and reduce the risk of future heart disease. The exosome treatment appears to be safe based on other studies, but like any medical treatment, there may be side effects. \--- How Long Will the Study Last? The main treatment happens during one visit, with follow-up visits for 1 week to check on participants' health and see if the treatment is working. This research may lead to new ways to protect women's heart health after pregnancy complications.