Does congenital hypothyroidism cause a higher incidence of neonatal morbidities?

Congenital Hypothyroidism and Neonatal Comorbidities

Discussion and Context

Research has shown that congenital hypothyroidism carries with it a higher risk of chronic comorbidities and neurological issues than found in the general population.¹ A nationwide population-based register study in Finland examined the incidence of congenital malformations, other diseases, and use of prescription medications in people with primary CH.²

Methods and Results

Danner et al analyzed four national population-based registers in Finland: the Prescription Register, the Care Register for Health Care, the Medical Birth Register, and the Register of Congenital Malformations, which provided decades of data. The registers can be cross-referenced thanks to a unique personal identity code assigned to every permanent resident in the nation. Researchers included all CH diagnoses across the registers up to 2018 and all drug prescriptions through 2017.

They collected diagnoses of neonatal and chronic diseases in 438 patients and 835 matched controls across a median of 11.6 years and an age range of infancy to 23 years of age.

Newborns with CH had a higher incidence of jaundice (11.2% and 2.0%; P<0.001), hypoglycemia (8.9% and 2.8%; P<0.001), metabolic acidemia (3.2% and 1.1%; P=0.007), and respiratory distress (3.9% and 1.3%; P<0.003) when compared with the control group. The analysis found congenital malformations in 15% of the patients with CH, twice the rate of the matched controls, with had an incidence rate of 7.4%. Circulatory and musculoskeletal systems were most often impacted. Hearing loss and developmental disorders also occurred at a higher rate among the CH cohort. These patients and the controls subjects used antidepressant and antipsychotic drugs at similar rates.

Practical Takeaways

Patients with CH have a greater incidence of neonatal morbidity, congenital malformations, and neurological disorders than patients without CH. The study found no evidence of severe psychiatric disorders among patients with CH. The research was published in The Journal of Clinical Endocrinology & Metabolism.²

Related Research and Perspectives on Congenital Hypothyroidism

• A discussion of the challenges in diagnosis and treatment of CH in preterm newborns. Frontiers in Endocrinology

• The 2020-2021 Consensus Guidelines Update on Congenital Hypothyroidism from the ENDO-European Reference Network Initiative was designed to optimize detection, diagnosis, treatment, and follow-up of children with all forms of CH according to the most recent evidence. Thyroid

• Use of levothyroxine was associated with a significantly higher risk — one and a half times — of developing pre-eclampsia when compared with women not being treated with the medication. Hypertension in Pregnancy