It's impossible to know. There are some workarounds, depending on specifically what you're dealing with.
Immobilization:
Right now, only oversized Testicles can immobilize Steele. The
Hoverboard and
Hardlight Anti-Grav Jock negate the status.
If Breasts could Immobilize, I expect the
Hardlight Anti-Grav Bra would work similarly.
Bulky Belly:
The
Breed Hungry Perk reduces belly weight from Pregnancies by 25%.
It's possible to increase Pregnancy speed to 10.5x (
Laquine Ears + Synth Womb + Incubator + Breed Hungry), or skip them entirely via Maternity Wait at the Tavros Apartment.
Vaginal Cumflation can be avoided via the Prostitute Pro. The
Honeypot Perk makes you reduce Oral Cumflation 5x faster, but makes your breasts grow.
I don't think it would be unreasonable to have some kind of Anti-Grav Maternity Shirt or Belt or something, but to my knowledge, nobody's written anything like that.