Neonatal testicular torsion after severe perinatal asphyxia treated with therapeutic hypothermia

Neonatal testicular torsion (NTT) has been postulated to occur as a result of hyperactive cremasteric reflex, which can be caused by fetal stress; however, no study has reported severe perinatal asphyxia causing NTT. We report about a male neonate with severe perinatal asphyxia treated with therapeutic hypothermia who showed left testicular torsion on the 16th day of life. We could not determine when the torsion occurred; however, we hypothesized that it occurred during the perinatal period because both perinatal asphyxia and therapeutic hypothermia could be risk factors for testicular torsion. NTT has been considered to occur as a result of a hyperactive cremasteric reflex on the loose fixation of the tunica vaginalis to the scrotal wall, and both fetal stress and low temperature have been considered to cause cremasteric reflex. NTT lacks noticeable signs and symptoms; thus, it can be overlooked in severe cases, as in our patient. Therefore, physicians treating male neonates with severe perinatal asphyxia with or without therapeutic hypothermia should examine their scrotum considering NTT. •Both perinatal asphyxia and therapeutic hypothermia could be risk factors of NTT.•The scrotum of male neonates with severe perinatal asphyxia must be examined daily.•Physicians should consider the possible occurrence of NTT.