Konjenital hipotiroidi sıklığı ve klinik sonuçları: Muğla İlinde yenidoğan tarama verilerine dayalı retrospektif bir çalışma

Objective: To evaluate the incidence, clinical characteristics, and treatment outcomes of congenital hypothyroidism (CH) identified through neonatal screening in Muğla province, with a particular focus on differentiating between transient and permanent CH.Methods: This retrospective study included 95 infants referred between 2020 and 2022 due to elevated thyroid-stimulating hormone (TSH) levels detected through heel-prick screening. Demographic, clinical, and biochemical data were collected. Infants were classified either as diagnosed and treated CH cases or as having transient TSH elevation without requiring treatment. Among the treated cases, CH was further categorized as transient or permanent based on follow-up findings. The predictive value of the levothyroxine (LT4) dose at six months of age was also analyzed.Results: The average annual incidence of CH was 114.4 per 100,000 live births. Of the 95 infants, 33 (34.7%) received treatment for CH, while 62 (65.3%) had transient TSH elevation and did not require treatment. Among the treated cases, 19 (57.6%) were diagnosed with permanent CH and 14 (42.4%) with transient CH. The mean LT4 dose at six months was significantly lower in transient cases compared to permanent ones. LT4 dose cut-off value of 3.35 µg/kg/day at six months demonstrated high sensitivity and moderate specificity in predicting transient CH.Conclusion: The incidence of CH in Muğla province exceeds global averages, with a notable proportion of transient cases. The LT4 dose at six months may serve as a useful marker for differentiating between transient and permanent CH, enabling more individualized follow-up and management strategies.