Survival rate of extremely low birthweight infants and its effect on the amendment of the Eugenic Protection Act in Japan

Abstract

Because of the increasing survival rate of extremely low birthweight infants in recent years, the viability limit in the Eugenic Protection Act in Japan was amended from 24 to 22 completed weeks of gestation. The Japan Pediatric Society's survey on the outcome of infants born in 1990 focused on infants born before 24 weeks gestation and less than 500 g. The survival rates of infants born in 23, 22 and before 22 weeks gestation overall at 511 hospitals throughout Japan were 43/118 (36%), 3/36 (8%) and 0/8 (0%), respectively. Of 16 infants, none weighing less than 400 g at birth survived but 16 (12%) of 50 infants between 400 and 499 g survived. Up-to-date statistical data is essential to the amendment of the concept of viability and subsequent ethical decision-making on extremely low birthweight infants.