LAUSR

Care of preterm infants with extremely low birth weight (BW) and having intact survival is still a challenge for neonatologists. In this issue of Pediatrics and Neonatology, Nagara reported the survival rate and the outcome of preterm infants with a BW of 500 g in a single institute during a 10-year period. Their strategy regarding the timing of delivery of live or stillborn infants with a BW of 500 g is to deliver cases where continued pregnancy would compromise maternal health or where nonreassuring fetal status is identified. The survival rate was 80% among live births, and the results of developmental assessments of 3-year-old children were 29% normal, 43% mild disability, and 29% severe disability. All the tiniest babies were also the most immature ones, and they would die if they did not receive any resuscitation or life support after birth. The approach regarding the care of the most immature babies varies around the world. In Japan, the limit of viability as defined in the law is 22 completed weeks of gestation. Preterm babies with a gestational age of 22 weeks will be resuscitated and admitted to the intensive care unit. The differences in the approaches related to the most immature babies result in the variation of survival rates in different countries and regions. When counseling with parents, both survival rate and long-term neurodevelopmental outcomes are important for decision-making in the management of the most immature or the tiniest babies. A systematic review and meta-analysis focusing on neurodevelopmental outcomes of the most immature babies demonstrated that the most commonly observed neurodevelopmental disability is cognitive impairment, followed by cerebral palsy. Vision and hearing deficits occur less frequently. In Japan, the new Kyoto Scale of Psychological Development (KSPD) test was used for neurodevelopmental evaluation. The KSPD test was used only in Japan, which makes it difficult to compare the results with other commonly used tools worldwide. Nagara reported that 43% (3/7) of survived patients had mild neurodevelopmental disability. In view of the developmental quotient (DQ), one of the three patients was in the