The progression of salt‐wasting and the body weight change during the first 2 weeks of life in classical 21‐hydroxylase deficiency patients

Background One of the major purposes of newborn screening for 21‐hydroxylase deficiency (21OHD) is preventing life‐threatening adrenal crisis. However, the details of adrenal crisis in newborns are not precisely documented. Aim We aimed to clarify the clinical details of salt‐wasting in newborn 21OHD patients. Methods Based on the follow‐up survey of the screening in Tokyo from 1989 to 2017, we retrospectively analysed the conditions of classical 21OHD neonates before the initiation of therapy. Results One hundred classical 21OHD patients (55 male, 45 female) were analysed. The age at the first hospital visit was 0–20 days with sex difference (male: 9.0 ± 3.5 days; female: 6.2 ± 3.9 days). Thirty‐seven (37.4%) patients exhibited severe salt‐wasting (SSW), that is, Na 7 mEq/L or Na/K ratio