Table 1.

Summary (part 1) of the studies that have assessed neurocognitive and neurodevelopment of the child born to mothers with Gestational Hypothyroidism (GHT) and treated with appropriate dose of levothyroxine throughout pregnancy.

Type	Name of the study	Definition of GHT	Sample size	Treatment	Time of initiation of therapy
RCT*	Lazarus et al. (56) CATS-I trial	TSH* > 97.5th percentile Or/and fT4* < 2.5th percentile	794	Starting dose of 150ug of levothyroxine per day (adjusted as necessary)	Median gestational age of 13 weeks + 3days
RCT	Hales et al. (63) CATS-II trial	TSH > 97.5th percentile Or/and fT4 < 2.5th percentile	449	Starting dose of 150ug of levothyroxine per day (adjusted as necessary)	Median gestational age of 13 weeks + 3days
RCT	Hales et al. (62) (CATS-I trial cohort)	TSH > 97.5th percentile Or/and fT4 < 2.5th percentile	475	Starting dose of 150ug of levothyroxine per day (adjusted as necessary)	Median gestational age of 13 weeks + 3days
RCT	Casey et al. (55)	SCH* –> TSH >= 4.0mU/L with normal fT4	677	Starting dose of 100ug of levothyroxine (adjusted as necessary)	Mean gestational age of 16.7 weeks
		IH*–> fT4 < 0.86ng/dL with normal TSH	526	Starting dose of 50ug of levothyroxine (adjusted as necessary)	Mean gestational age of 17.8 weeks
Prospective Cohort	Zhou et al. (61)	TSH > 97.5th percentile and TPOAb (+) *	466	Levothyroxine treatment targeting TSH values of 0.1-2.5mU/L	Before conception and after conception (mean gestational age 13.5 weeks)

*RCT, Randomised Controlled Trial; TSH, Thyroid-Stimulating Hormone; fT4, Free Thyroxine; SCH, Subclinical Hypothyroidism; IH, Isolated Hypothyroxinemia; TPOAb (+), Thyroid Peroxidases antibodies.