. 2020 Sep 30;93(4):501–515.

Table 3. Changes in TH depending on the trimester.

Hormone	I trimester	II trimester	III trimester
TSH^a	- - -	- -	-
T3^b	++	+++	+++
T4^c	++	+++	+++
fT3^d	-	- -	- -
fT4^e	-	- -	- -
TBG^f	++	+++	+++
hCG^g	+/++	++	++

^athyrotropin, ^btriiodothyronine, ^cthyroxine, ^dfree triiodothyronine, ^efree thyroxine, ^fthyroxine-binding globulin, ^gchorionic gonadotropin, + increased level, - decreased level