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 ExtenderBattery Negative Cable Disconnection and Connection Low Voltage Battery
Battery Negative Cable Disconnection and ConnectionCalloutComponent NamePreliminary ProceduresTurn on the radio and record all of the radio station presets.Ensure all lamps and accessories are turned off.Ensure the ignition switch is in the OFF position, and remove the ignition key.1Negative Battery ...