Will low levels of TSH affect my fertility?

[Want2BMom]

I am a 26-year-old female who was diagnosed with papillary thyroid cancer two years ago.  I have since had my thyroid completely removed and underwent two doses of radioactive iodine-131.  My endocrinologist has me on a high dosage of Levothyroxine (150 MCG) as part of my cancer treatment.  My T4 is 1.56 and my TSH is 0.02  It has been nine months since my last dose of radiation and my endocrinologist told me I could try to get pregnant.  My husband and I have been trying for several months but aren't having any luck.  I told my endocrinologist at our last visit but he refuses to lower the dosage of Levothyroxine insisting that it will not affect my fertility.  My husband and I have one child that we conceived before I was diagnosed with thyroid cancer, so I know we are both capable of having a child.  However, I'm worried that my high dosage of Levothyroxine is preventing me from conceiving.  Are my TSH levels too low to conceive?  How will this high dosage of medication affect my fertility?

[roheena]

A related discussion, high T4 was started.

[Mark Lupo, M.D.]

The low TSH (hyperthyroidism) may be influencing conception rates -- if there is NO evidence of persistent/recurrent PTC (pap thy cancer) then it is reasonable to let the TSH drift up to around 0.2 -- again this depends on the status of the PTC.  Of course, there may be other issues at work.  The I-131, however,  typically does not cause infertility

[Lake Lover]

I see nobody has commented which they obviously don't know.

You should address your concerns with your gynocologist as TSH testing would probably be something they test with pregnant women.

I would think if your FT-3 and FT-4 are in a decent range the TSH should not have any effect on getting pregnant.  I completely ignore TSH and only dose by FT's.