Li M, He Y, Mao Y, et al. - Researchers aimed at ascertaining if subclinical thyroid dysfunction before conception is associated with adverse pregnancy outcomes.

• Retrospective cohort study of 50,217 women without prior thyroid disease who became pregnant within 1 year after undertaking a routine TSH test.

• Composite adverse pregnancy outcomes (CAPO), comprising pregnancy loss, small for gestational age, large for gestational age, and preterm birth, were reported in 24.19%.

• Preconception TSH levels and pregnancy outcomes were identified to exhibit non-linear associations.

• Risk for CAPO appeared higher among women with subclinical hypothyroidism before conception, while a higher risk of preterm delivery was recorded for those with subclinical hyperthyroidism.