Seat belts work for everyone, including pregnant women. Like all occupants, they are more likely to be seriously injured if they do not wear seat belts.

A pregnant woman should wear a lap-shoulder belt, and the lap portion should be worn as low as possible, below the rounding, throughout the pregnancy.
The best way to protect the fetus is to protect the mother. When a seat belt is worn properly, it is more likely that the fetus will not be hurt in a crash. For pregnant women, as for anyone, the key to making seat belts effective is wearing them properly.
Lap-Shoulder Belt
Seat Belt ExtenderClimate Control Systems (CCS)
The heating, cooling, and ventilation for the vehicle can be controlled with
this system.
Fan Control
MAX Defrost
Defrost/Defog
A/C (Air Conditioning)
Temperature Control
Driver and Passenger Heated
Seats (If Equipped)
Recirculation
...