Jwa SC, et al. - Researchers examined how male subfertility is associated with the risk of major birth defects in children born after in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Using data from the Japanese assisted reproductive technology registry, they retrospectively studied data of 59,971 fresh embryo transfer cycles registered from 2007 to 2014 that resulted in singleton live births, still births, or selective terminations. In 626/59,971 (1.04%) cases, major birth defects were reported. Association of male subfertility with significantly greater risks of hypospadias (3/3163 [0.09%] vs 4/28,671 [0.01%]) and atrial septal defects (4/3163 [0.13%] vs 9/28,671 [0.03%]) compared with fertile men was reported, among IVF cycles. Results thereby suggest a possible role of underlying male subfertility in the risk of major birth defects related to ICSI and IVF.