If the TSH
levels have increased it means
1.. Either you stopped taking medicine for hypothyroidism
2.. Or the dose being given for control of hypothyroidism is less.
You must make it a point that hypothyroidism is corrected properly otherwise you may find difficult for pregnancy
The ideal levels of TSH,for conception,should be around 2.
You must consult an endocrinologist
for proper evaluation and treatment of your wife's hypothyroidism along with a regular advise from your Gyneobs.