From the hormonal standpoint, multiple miscarriage
can occur due to suboptimal thyroids, progesterone
and metabolic disturbances. Considering your fluctuating TSH, I would like to rule out Autoimmune Thyroiditis, another possible cause of miscarriage.
I would consider switching you from your present tbyroid meds to a combination of T3 and T4 and investigate for other hormone and metabolic deficiencies.