Can estrogen priming therapy during IVF treatment lead to transient TSH elevation without clinical hypothyroidism?

A large number of hypothyroid women taking Levothyroxine will need to increase the dose of Levothyroxine after IVF. IVF results in extremely high levels of estrogen, which increases the thyroid-binding globulin that in terns require an dose increase of about 30%. Generally, it is recommended to increase the dose of T4 by 2 pills per week (9 pills = 29% increase). Remember that subclinical hyperthyroidism has no adverse effects on pregnancy, while even mildly low levels of thyroid are felt to potentially have an adverse impact on fetal development. It is ok to overshoot the dose increase. I usually recheck TSH Free T4 in about 2-3 weeks to make sure the TSH is not elevated and then again as soon as pregnancy is confirmed (my practice - not i...