I’m considering maybe we just don’t live together once we have the child so I don’t have to be around the dogs but when I broach this with him, he was offended and did not agree at all with the idea.
For a start, he doesn't get to decide this, you do. You don't need his permission to live separately. If it's a deal-breaker for him then you'll split up.
There shouldn't be fur everywhere, that's a lack of housekeeping and a lack of dog care. If you've got furry pets you need to hoover daily, it's that simple. If he's not going to do that, his house will be unclean. The covers on the sofas need washing, if they're not removable the sofas will need replacing. The smell will be in the fabric, especially if the dogs are allowed to sit on the sofas. The walls need wiping down.
Mopping the floor, wiping the surfaces, cleaning the bathroom and running the hoover round weekly is the bare minimum that people without pets should be doing, not some major effort on his part.
The dogs don't need to go to the groomer but they do need to be groomed. Being old is no reason not to do it. If they're badly trained or their hair is a mess, they may find themselves getting pulled around at the groomers so they can get the job done in the allotted time. They're not there to train people's pets. Long term the owner should be doing that at home, so they learn to stand quietly whilst being groomed. So to avoid any rushed handling, offer to pay double for each dog so they can have a longer appointment and things can be done more calmly. It's not acceptable just to leave them ungroomed, for a start their nails will become overgrown and their toes deformed which will affect their ability to walk pain-free.
Alternatively, he can groom them himself. From a health perspective it's not rocket science. A slicker brush (no other kind, they will pull and hurt) to get tangles and dead hair out, a comb to check for any tangles that have been missed so you can go back in with the slicker brush, nail clipping (he'll have to learn where the vein is so he can try to avoid cutting it), any matts cut out with scissors. Then shampoo and blow-dry, using the slicker brush again as you do. It may not look the prettiest, especially if a lot of matts have been cut out, but from a health perspective it's adequate. Leaving them ungroomed, especially an old dog that can't groom itself properly, is neglect. He needs to raise his game. Brushing weekly, shampooing every 6 weeks.
It doesn't matter that he can't smell the dogs, you can. Probably so can everyone else, they're just not pregnant and nauseated by it and are too polite to say anything. If someone is telling him his house stinks, he should be paying attention to that.
If the old dog is dying of some condition and is too badly trained to groom or is too upset by the process, then the time to PTS is now. Leaving it until the last minute is something owners do for their own sake, not their pets' sake, and it's selfish.
No relationship is perfect but you need to start as you mean to go on, otherwise your life will be hell. Don't tolerate being expected to live in unclean conditions just because he's a lazy pet owner. It won't get better over time. Either he steps up now and starts doing things properly or you don't live together. He shouldn't be acting like mopping the floor once a week is doing you a favour. This isn't really about the dogs, this is about his attitude towards housework as much as it is about pet care.
Don't live a miserable life with a waste of space man. You've got your DC so you'll have to co-parent with him, but you can and should find someone better as your life partner, if this man won't step up and start living like a civilised human being. I don't know how old he is but he's over 18 and about to become a father, it's time to grow up. If he's over 25-30, bad news, he's not going to - this is him and he is unlikely to ever change.
If he won't step up, it's better to break up now and try to remain friends, than to wait until you're at the point of rowing about housework and pets regularly and you've come to despise the sight of him. Be lead by your head instead of your heart, look at things from a practical perspective and act accordingly - because love does not conquer all, that's romantic nonsense that soon fades in the face of your partner neglecting you and DC.