You're right, but per the post, this man's girlfriend was still struggling with elevated prolactin and it seems there is no clear "cure" for her at this point. She's been through multiple rounds of treatment and faces the prospect of more.

I didn't mean to sound hopeless but when you're in the midst of suffering from a medical condition and the future is uncertain, having your closest person focusing on something that isn't the immediate priority and that you may never be able to do can make you feel really horrible/inadequate.

Imagine you're the man's girlfriend. How would it make you feel if your SO was still talking to you about children at this stage?