Incidence and Risk Factors of Congenital Hypothyroidism Among Newborns Delivered at Phrapokklao Hospital: A 7-year Retrospective Study

Abstract

BACKGROUND: According to the national newborn screening program of Thailand, all infants are required to undergo blood screening for congenital hypothyroidism. However, no prior data have been collected on this population in Chanthaburi Province, resulting in a lack of baseline information for local healthcare planning and service development.

OBJECTIVES: To determine the incidence and perinatal factors associated with congenital hypothyroidism among infants born at, or referred for initial screening to, Phrapokklao Hospital between 2015 and 2022, and to follow affected infants for at least three years in order to evaluate treatment outcomes as either transient or permanent.

METHODS: This retrospective cohort study was conducted using newborn, maternal, and follow-up data. Descriptive statistics and Pearson’s Chi-square test were applied, with statistical significance set at p<0.05.

RESULTS: Among 29,967 screened infants, 72 were diagnosed with congenital hypothyroidism, yielding an incidence of 1:416. Factors significantly associated with the condition included gestational age less than 37 weeks, birth weight under 2,500 grams, the presence of congenital anomalies, particularly Down syndrome, and maternal hypertension. Follow-up for at least three years showed that 22 infants had transient hypothyroidism, whereas in 16 cases, the condition was permanent, highlighting the importance of an effective follow-up system.

CONCLUSIONS: The incidence of congenital hypothyroidism at Phrapokklao Hospital was higher than that reported in other studies, likely due to its role as a tertiary referral center for high-risk pregnant woman and newborns. Therefore, effective screening, appropriate clinical care, and close follow-up are essential to prevent long-term adverse developmental outcomes.

Thaiclinicaltrials.org number, TCTR20250505005