Hi Collo,
Saw your post in the "wellbeing" board. Thyrotoxicosis (excess thyroid hormone, iodine and antibodies) has a major effect on pregnancy hormones. I am thyrotoxic currently, and recently found out I am pregnant. I have a 5x greater risk of miscarriage and a 7x greater risk of my baby having birth defects. Hyperthyroidism DOES affect fertility in a negative way, but it does not necessarily cause it. I hope for you it is as simple as that. Best wishes.
<3 serene

My initial post on the subject is here:
https://www.bellybelly.com.au/forums...ml#post1209827
and here:
https://www.bellybelly.com.au/forums...thyroid-2.html