Lee TH, et al. – This study is performed to detect the SEA–type α–thalassemia in embryo biopsies by digital polymerase chain reaction (PCR). The SEA–type deletion in cultured embryos can be sensitively diagnosed with the digital PCR procedure in clinics. The adoption of this robust pre–implantation genetic diagnosis (PGD) method could prevent the implantation of in vitro fertilization (IVF) embryos that are destined to develop Bart's hydrops fetalis in a timely manner. The outcomes also help inform future development of a standard digital PCR procedure for cost–effective PGD of α–thalassemia in a standard IVF clinic.