Greg Olsen, tight end for the Carolina Panthers, and his wife tell the story of their unborn twin who was diagnosed with Hypoplastic Left Heart Syndrome. As a Program, we've had many inquiries from people expecting twins - one affected with HLHS. In an article published in Ultrasound Medicine, researchers reported the difference in prevalence between twin pregnancies and singletons. According to this article, the prevalence of HLHS in the general population per 1000 live births (non twin) is 0.14 or about 1/7000. In twin pregnancies, (both mono and di-chorionic pregnancies) the incidence was higher than in the general population, at about 1/580 to 1/830 fetuses. Olsens' amazing story includes the mention of an experimental procedure of Fetal Aortic Balloon Valvuloplasty. Currently, this is not an option for twins because of risk to the unaffected twin.