Weight loss for hypo is very hard. Easy weight loss and hard to gain is typically associated with Hyper and Graves. Hashi's and hypo are the other way. Hard to lose easy to gain.
To respond to the original post, I have been hypo for my previous 4 pregnancies. I did not experience fertility problems associated with thyroid disorder. I only recently got diagnosed with Hashi's because I demanded it. I probably had it with my previous pregnancy. My levels are almost impossible to stabalise with medicine. Since being diagnosed with Hashi's this past year, we had to up my dose to a new all time high which is too high for my height and weight to 200 mcg. Just did a blood draw last week and we now have to up it to 250mcg. I am currently pregnant with twins and in the first trimester. My levels typically do finally stabalize at my second trimester and do not need to be readjusted until a few weeks after delivery when my hormones will go out of whack again flucuating from birth and breastfeeding. And then will readjust dose and stabalize as long as I am breastfeeding. Once I stop, I go back and forth between doses again and need constant checking again. Ironically, my levels do the best during pregnancy and breastfeeding.