I'm not sure of the correct answer, but in our case...we were up to our 8th fertility treatment (4 IUI, 1 ICSI, 1 FET then back to IUI's) and we were becoming a little more relaxed. The night before our 8th attempt DH went to a mates house for 'just a couple if drinks' which turned out to be so many he had to be driven home. I was sooo mad and expected when the fertility specialist got his 'part' ready they'd say it wasn't viable or something. Turned out those 'swimmers' had no problem with it at all. His result was the highest percentages they'd been and one of his swimmers finally reached the goal...we finally got a nice strong positive result. Then when DS1 was 12months- I'd finished BF'ing 4weeks prior (so that likely helped ALOT) but once again after a few drinkies from both myself and DH...I found out a few weeks later we had conceived our DS2....and naturally.
So it might be thats its a big no-no (i have no idea...my fertility specialists were still telling me it was still ok for me to have a wine....even including on the day we'd had the inseminations done...they'd say go home, put your feet up, have a glass of wine and relax), but obviously it didn't hinder our TTC journey.
But as others have said it may depend on the extent your DH is drinking. My DH usually does do a couple of beers a night which i have no problem with he works long challenging days so a couple of beers to help him relax i think is fine here and those almost all night drinking things were rare (even more rare these days of course). In our case we needed to become more relaxed (but i guess not too relaxed...still within reason most of the time) about TTC as we did the 'serious and more controlled' approach and all it did was start to take us to a dark place.
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