ESPE2021 Free Communications Thyroid (6 abstracts)
Background: More than half of newborns with central congenital hypothyroidism (C-CH) have moderate-to-severe hypothyroidism in the neonatal phase, requiring immediate thyroxine therapy to prevent brain damage. The Israeli newborn screening for CH is based on the measurement of total T4 (TT4) followed by TSH measurement. However, when TSH is within the normal range the physicians are not informed of the results and therefore the diagnosis of C-CH and initiation of L-T4 therapy are significantly delayed. This study aimed to assess the prevalence of C-CH in Israel and to characterize clinical features, neonatal screening results, the outcomes of children with C-CH.
Methods: In this multicenter, nationwide retrospective study data on 96 subjects (54 males) diagnosed with C-CH were collected from medical records from 9 Pediatric Endocrine Hospital Centers in Israel. Neonatal screening results were retrospectively retrieved from the computerized records of the National Newborn Screening Program between 2008 to 2021.
Results: The estimated prevalence of C-HC in the screened and studied population was 1: 52000 live births and in the Northern region of Israel, where the consanguinity rate is high, the prevalence was 1: 22000 live births. Seventy nine (82%) had combined pituitary hormone deficiencies (CPHD). The remaining 17 (18%) subjects had Isolated C-CH. Median and IQR (interquartile range) age at initial endocrine evaluation was 51(8-575) days. Median TSH and FT4 levels were 3.19 (1.78 - 5.25) mIU/l, and 9.00 (6.84 - 9.97) pmol/l respectively. At diagnosis 66% of patients had FT4 levels below 10 pmol/l. Neonatal screening results were available for 44 subjects with median TSH level 3.83 (2.56 - 6.69) (normal range for newborns (<20 mIU/l)) and TT4, for in term patients, was 6.7 percentile (6.68 (5.06 - 9.05)) mcg/dl. The diagnosis in the newborn period was based on signs and symptoms of hypopituitarism (40.8%), micropenis (23.5% of males). Growth failure (30%) and neurodevelopmental delay (7.8%) were the main reasons for diagnosis during infancy. Significant number of children 36 (37%) with CPHD and Isolated C-CH had neurodevelopmental sequalae included: mental retardation (18% and 7.7%); learning difficulties (27% and 23%), delayed speech (32% and 50%) and motor clumsiness (25% and 23%).
Conclusions: 1. Despite efforts to improve detection of all forms of congenital hypothyroidism with newborn screening, we found a significant delay in the diagnosis of C-HC. 2. At diagnosis, over half of the patients with C-CH had severe to moderate hypothyroidism, and a significant number of patients suffered from neurodevelopmental sequalae.
22 Sep 2021 - 26 Sep 2021