A Nationwide Study of the Prevalence and Initial Management of Atypical Genitalia in the Newborn in Scotland

Abstract

Provision of optimum healthcare for infants with atypical genitalia requires a clear understanding of the occurrence of this condition. The objective of this study was to determine the prevalence of atypical genitalia and its initial management. A prospective, electronic survey of clinicians within managed clinical networks in Scotland was undertaken between 2013 and 2019. Notification from clinicians was sought for term neonates requiring specialist input for atypical genitalia. Additional information was also sought from the 4 regional genetics laboratories that provided details for neonates who had an urgent karyotype performed for atypical genitalia or sex determination. In total, the study identified 171 term infants who required some investigation for atypical genitalia in the neonatal period, providing a birth prevalence of 1:1,881 term births. Of the 171 infants, 97 (57%) had specialist input over the first 3 months of life, providing a birth prevalence of 1:3,318 term births that received specialist input for atypical genitalia. A total of 92 of these 97 cases had complete 3-month follow-up data, 62 (67%) presented within 24 h of birth, and age at presentation ranged from birth to 28 days. Age at sex assignment ranged from birth to 14 days, and in 63 cases (68%), sex assignment occurred at birth. Thus, the birth prevalence of a case of atypical genitalia where sex assignment was reported to be delayed beyond birth was estimated at 1:11,097 births. In 1 case sex was re-assigned at 3 months. Atypical genitalia requiring specialist input within the first month of life are rare in term newborns, and in only a third of these cases, sex assignment is delayed beyond birth. This study provides new clinical benchmarks for comparing and improving the delivery of care in centres that manage these conditions.