Women with miscarriage at higher risk for subclinical hypothyroidism

UK: Women with a history of miscarriage or subfertility are at a higher risk for subclinical hypothyroidism, according to a recent study in the Journal of Clinical Endocrinology & Metabolism. According to the study, the prevalence of subclinical hypothyroidism was about 20% when using a TSH cutoff of 2.5 mIU/L, in such women.

It remains uncertain whether asymptomatic patients be screened for mild subclinical hypothyroidism (SCH) or thyroid peroxidase antibodies (TPOAb). In the absence of evidence of benefit with LT4 [levothyroxine] treatment and possible suggestion of harm, whether screening should be performed at all in asymptomatic individuals remains questionable. There is a need for large randomized trials to establish if preconception LT4 treatment of mild SCH with or without TPOAb positivity is beneficial.

Subclinical hypothyroidism represents an early stage of thyroid dysfunction. It can lead to preterm birth, miscarriage, subfertility, perinatal mortality, and preeclampsia. Thyroid peroxidase antibodies also have been associated with adverse pregnancy outcomes, and their presence increases the risk of subclinical and overt thyroid disease in pregnancy

Rima K Dhillon-Smith, University of Birmingham, Birmingham, UK, and colleagues conducted the study to describe the prevalence of and factors associated with different thyroid dysfunction phenotypes in women who are asymptomatic preconception.