Don't use your hands to push him off. To a dog, hands are the world's greatest treat, so you're rewarding him for jumping up. Try one of these, whichever is safer:
1. Bring up your knee as he jumps up so he bumps his chest on it. Then pet him BRIEFLY when all four feet are on the floor. Red Light, Green Light. If he jumps up 100 times, repeat 101. Chances are you will only have to repeat 3 - 4 times. When he sits and looks at you in a puzzled way, pet and praise big time! But be ready to correct again.
2. When he jumps up, walk TOWARD him, bump into him. This will knock him off balance and he will scramble to back up and get out of your way. Pet and praise when all 4 feet are on the floor. Prepare to repeat as above.
3. Turn away from him and walk away. Leave him nobody to put his feet on. Watch over your shoulder. Pet and praise when all 4 feet are on the floor.
Notice a theme in all this? Jumping up is seeking attention. Pet him BEFORE he jumps up. Catch him doing it RIGHT. Good luck!
The only worry I'd have with the first one would be him knocking me down (he is DENSE, haha), but that makes sense. The second one, I'd genuinely have to get into a body slam position and charge with my full weight and then some to actually knock him off balance. He is more than half my size and has very good footing (he is 75ish lbs, and I am 127lbs pre-pregnancy, plus I am tall so I have a higher, more tippable center of gravity).
I do the third one all the time, unless I actively need to do something like get his water bowl from within the end of his cable, because I can't spend twenty minutes trying to get it.
I was advised by more than one person to grab his scruff and force him onto his back when he jumps. It mostly worked for my husband (so he says, not entirely sure when I'm watching them out there, lol), but it doesn't seem to be effective when I do it, so I do use the "turn around and ignore" whenever it's applicable (I've also pushed him down, then done the ignoring, which works better). But yes, the ignoring is very helpful, I agree it seems to work MUCH better than pushing down when I can actually apply it. I also try to pet before he makes the mistake whenever I can!
Often times, he will stand for a few moments when you pet him with four on the floor, then he'll spin really tight a couple of times, which wouldn't be disruptive if he weren't capable of knocking legs out from under you from a standstill, and leave painful bruises with his big head.

I should note, he is fairly decent at knowing that he should keep his butt planted while I walk up. I stop when he gets excited, and he sits back down (being at the end of a cable is very helpful). I'm able to pet him then. But, he does the spinning, and once we move on from petting or I try to take a few steps, he starts jumping because he'd love to cuddle and play (which is another thing I'd be doing a LOT more with him if I weren't worried about getting jumped on in the wrong spot). The biggest issue is his size. If he were 20lbs lighter or I weren't pregnant, it would be a fairly different story (if I weren't pregnant, you bet I'd walk into him when he tries to jump, and I'd be willing to take longer to do things and be in the "striking zone" for longer, practicing ignoring his silliness).
I'll keep in mind that the hands aren't the best way to go in the future and use my hands to shield my front instead of push him, and I'll keep the rest in mind for next spring when I'm not sharing my belly with a wiggly little baby and I can really apply it.

In the meantime, I'll see what IS possible in each situation, too. Thank you!