I think there are a lot of things to consider in this situation.

I wasn't actually 100% certain from your post as to whether you lived in your FIL's house or if he lived in yours....but if you do in fact live in your FIL's house, then it becomes a bit more complicated I think as you have to respect his wishes. Having said that, you could implement some fairly simple training exercises in order to help the dogs stay away from baby-related things, or to not be startled by the sound of the baby crying.

When I was PG with Jacob, we had 2 cats and a dog and we were very concerned about all of them......not least of which being our oldest cat who was blind (he sadly died a few weeks ago). The cats had been inside all the time, and the dog inside only of an evening....outside for the rest of the time. What we ended up doing with the cats was relocating them outside, but they actually had a sheltered area where they slept (and were safe etc and could not get out of during the night as we locked them in), but they were allowed to come inside as much as they liked. Once Jacob was born, DH brought home some of Jacob's clothing and laid them in different spots around the house......he even put the rocker in the lounge room and sat his clothes in it so that the cats got used to not only the rocker being there, but also Jacob's scent. We ended up having NO problems whatsoever with our cats!

So I guess my suggestion is perhaps to try some basic training exercises (you could speak to a vet about this) and also do some things like bring home articles of clothing from hospital so that the dogs are familiar with the scent and don't freak out when you come home..........