Birth weight percentiles in infants with neonatal-onset prolonged neonatal hypoglycemia and persistent congenital hyperinsulinism

Objectives Prolonged neonatal hypoglycemia eventually resolving spontaneously is linked to perinatal stress, whereas persistent congenital hyperinsulinism is caused by genetic alterations leading to dysregulated insulin secretion. We investigated whether birth weight percentiles differ between both disorders. Methods Retrospective analysis of birth weight percentiles in infants treated for prolonged neonatal hypoglycemia (n=9) or persistent neonatal hyperinsulinism (n=78) in two referral centers (2001–2023). Results Infants with prolonged neonatal hypoglycemia had significantly lower birth weight percentiles than those with persistent congenital hyperinsulinism (median 16 [interquartile range 4–72] vs. 89 [50–98]; p=0.003). The area under the receiver operator characteristics curve describing the power to discriminate between infants with prolonged neonatal hypoglycemia and persistent congenital hyperinsulinism was 0.801 (95 % confidence interval 0.660–0.941), p<0.001. Among infants with prolonged neonatal hypoglycemia, 4/9 were small for gestational age (birth weight <10th percentile), while 36/78 infants with persistent congenital hyperinsulinism were large for gestational age (>90th percentile). However, close to half of infants in each group had normal birth weights for gestational age. Conclusions While birth weight percentiles reflect differing fetal growth patterns in these conditions, they are insufficient as standalone diagnostic criteria. Additional algorithms are needed for accurate early identification and discrimination.