Sara's twins were not growing at the same rate. They shared an amniotic sack and were not receiving the same levels of fluid. If not corrected, the babies risked heart failure or death. Sara was cared for at the Fetal Care Center, a collaborative center between St. Louis Children's Hospital, Barnes Jewish Hospital and Washington University School of Medicine. The condition, known as Twin Twin Transfusion Syndrome (TTTS) was so far along, that the less invasive correction - where excess fluid is drained from the sack - was not an option. Instead, Sara required a laser procedure to cut off the flow of fluid between babies, and equalize the fluid between them.