Screening for Delayed Thyroid Stimulation Hormone Rise and Atypical Congenital Hypothyroidism in Infants Born Very Preterm and Infants with Very Low Birth Weight - PubMed (original) (raw)

Screening for Delayed Thyroid Stimulation Hormone Rise and Atypical Congenital Hypothyroidism in Infants Born Very Preterm and Infants with Very Low Birth Weight

Bret Nolan et al. J Pediatr. 2024 Jun.

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Abstract

Objective: To determine among infants born very preterm (VPT) or with very low birth weight (VLBW) the incidence of alterations in thyroid function and associated comorbidities; the incidence of atypical congenital hypothyroidism (CH) requiring thyroxine therapy; and reference ranges for rescreening at 1 month of age.

Study design: A retrospective review of infants born VPT or with VLBW and admitted to UC Irvine Medical Center between January 1, 2012, and December 31, 2020. Repeat thyroid screening was obtained at 1 month of life (+10 days). Infants with thyroid-stimulating hormone (TSH) >5 μIU/mL or free thyroxine <0.8 ng/dL underwent follow-up testing and endocrinology consultation. Initial newborn screening (NBS) and repeat thyroid screening data were collected via chart review. Demographic data and short-term outcomes were abstracted from the California Perinatal Quality Care Collaborative database.

Results: In total, 430 patients were included; 64 of 429 patients (14.9%) had TSH >5 μIU/mL and 20 of 421 patients (4.8%) had free thyroxine <0.8 ng/dL. Logistic regression analysis identified small for gestational age (P = .044), patent ductus arteriosus (P = .013), and late-onset sepsis (P = .026) as risk factors associated with delayed TSH rise. Atypical CH requiring treatment through neonatal intensive care unit discharge was diagnosed in 6 patients (incidence of 1.4%); none were identified by NBS. The 90th percentile TSH for infants with extremely low birth weight (<1000 g) was 7.2 μIU/mL, and the 95th percentile for those with birth weight of 1000-1500 g was 6.1 μIU/mL; using these cutoff values identified all infants diagnosed with atypical CH with 100% sensitivity and 90%-95% specificity.

Conclusions: Abnormal thyroid function is common in infants born preterm. Those infants, including some with atypical CH, are missed by NBS. We recommend repeat thyroid screening with TSH at 1 month of age in infants born VPT or infants with VLBW to identify CH that may require therapy.

Keywords: VLBW infants; atypical hypothyroidism; congenital hypothyroidism; delayed TSH rise.

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Conflict of interest statement

Declaration of Competing Interest This study was funded through an intramural funding provided by the Division of Neonatology, Department of Pediatrics, University of CaliforniaIrvine. The authors reported no conflicts of interest.

Screening for Delayed Thyroid Stimulation Hormone Rise and Atypical Congenital Hypothyroidism in Infants Born Very Preterm and Infants with Very Low Birth Weight - PubMed (original) (raw)