TP im in no position to offer real advice here i just truly hope you guys get to the bottom of this, i want nothing more than to see you get your boy :heart: you are one of just a few people on this site who i feel really understands the level of GD that i myself went through (although with the opposite gender) reading your posts helped me in feeling like i wasnt alone in how extreme my own GD was.
i dont know if this will be of any help but a friend of mine has 3 children with her partner GBG, however.. he was previously married for around 10 years to another lady i also know, they tried for years to get pregnant-nothing, had ALL the tests done, she was normal but they got told that he was completely 100% infertile, sperm count as bad as it gets type thing.
long story short..they divorce in the end and he meets my other friend, shortly after shes pregnant (NOT planned) baby 100% is his and they have gone on to have 2 more babies (all unplanned so defo no IVF or other treatments)
i have no idea exactly how this has happened but just thought id share since you mentioned formerly infertile couples.
i agree with waiting on the IVF until you have more answers, i know its the last thing you want to hear but it would be awful for you to go through full blown IVF and still have it end in losses, you CAN carry a baby to term, there WILL be an answer to all of this, stay strong we are all with you 100% xx