Hopefully the test results will make this decision clearer for the consultant. Fingers crossed!
I'm popping in here to say that I don't usually hang out on mumsnet, but I checked out the thread for late April / May cycles (as I started my stims on the 26th May) and I came across your story, which is almost exactly my story! In this sea of frustration and disappointment, it was nice to see that someone is going through the same thing as me, and it made me feel less alone. Though in an ideal world, I would have wished for both of us to have a smoother sailing through this whole IVF process.
My journey started with our first stim cycle in August last year. Our tests going in were decent for our ages (both 35 last year, 36 now), and despite my husband having a varicocele, his sperm analysis looked decent so we gave IVF a go as we were. We ended up with 2 blastocysts, one of which resulted in a chemical and the other one failed to implant.
Before entering the second cycle, we did more tests and it showed that my AMH had halved after only 6-7 months dropping to 8.4, FSH increased over normal at 12, and now my husband's sperm analysis looks consistently bad (not terrible, but also not great). It didn't look great last year either on egg / sperm collection day, but we thought it was a fluke. Now it's consistently inferior and the varicocelectomy is recommended. But as you said as well, it's 50/50 whether it will actually lift the sperm parameters and in theory it could improve DNA fragm but no one really knows.
So because my parameters are getting worse, our consultant recommended that we get on with this IVF cycle instead of waiting to do the varicocelectomy (which takes another 3-6 months in recovery as I'm sure you know), but in the end he put the decision back on us which was incredibly frustrating for us. But we went ahead with his suggestion and we started our second cycle on the 26th, then my husband will do the procedure and we'll try again next year for a third time if this one doesn't work. And if the third cycle doesn't work either, we'll call it a day.
So far in this cycle, I've started with 6-7 follicles and today I had my Day 6 scan and it's looking like 6 are around 10 mm and one is smaller so not really counting on that one. I'm on Menopur + Gonal F and after the scan the consultant has decided to decrease my Menopur dose. I'm going back on Sunday and we'll see how that goes.
Good luck to everyone!