Routine serum thyroid-stimulating hormone testing-optimizing pre-conception health or generating toxic knowledge?

Monitoring subclinical hypothyroidism (SCH) in women is believed to be important in terms of preventing overt hypothyroidism and optimizing the health and cognitive development of their children. Current systematic reviews have suggested an association between maternal SCH and adverse obstetric and neonatal outcomes. However, initiating the administration of thyroxine during pregnancy has failed to demonstrate appreciable health benefits. Hence there are calls by professional endocrine societies for optimizing serum thyroid-stimulating hormone (TSH) levels pre-conception. The strategy of ensuring that serum TSH levels are below 2.5 mIU/l during the pre-conception period has generated considerable uncertainty partly because the recommended level of