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 ExtenderDriver or Passenger Seat Back Cover and Pad Replacement Seats
Driver or Passenger Seat Back Cover and Pad ReplacementCalloutComponent NameWarning:Refer toSIR Warning.Warning:Do not repair or replace the seat stitching or seams in theseat back trim cover with an internal mounted seat side airbagmodule. Replace the complete seat back trim cover from the OEM.Non- ...