Pregnancy Seat Belt Adjusters

Pregnancy seat belt adjusters, more accurately called seat belt positioners, are devices that redirect the lap belt so that the belt is no longer resting against the user's belly. This new routing is intended to reduce the pressure of the seat belt on the abdomen in a crash. 

At first glance this sounds like a good idea. The lap belt can potentially press against a fetus in a crash. Reducing that pressure would presumably make the fetus safer. However, the main cause of injury for unborn babies in crashes is placental abruption, a medical condition where the placenta detaches from the wall of the uterus. Placental abruption can result from a number of different factors, many of which are not related to the lap belt. Isolating the variable of the lap belt does not eliminate the risk of abruption. 

When using a pregnancy seat belt positioner, the user is modifying a safety system with a product that is not approved by the vehicle manufacturer. The seat belt is no longer being used the way it is designed, tested, and proven to save lives.

There is a great deal of evidence that wearing the seat belt properly increases safety for pregnant vehicle occupants in crashes. There is no evidence that seat belt positioners increase safety.

Many seat belt positioner advertisements claim that their product is crash tested. However, most manufacturers do not provide any crash test information. Without supporting documentation there is no way to know if the positioner was actually tested. Online retailers are not required to check the accuracy of statements made in product listings. Even if the positioner is listed on a reputable site, it still may not be crash tested.

"Crash tested" is a relatively loose statement. Simply stating a product is crash tested does not mean that it will perform well in a crash. When a consumer sees that a car seat "meets FMVSS 213" the manufacturer is promising the consumer that the car seat will perform to a set of standards. A seat belt positioner that simply says "crash tested" does not necessarily promise safety.

Seat belts are required to meet rigorous standards for design, construction, and crash performance. Drivers and passengers know they can trust that the seat belt is safe to use. Pregnancy seat belt positioners do not carry any of those guarantees. Manufacturers are free to build seat belt positioners with any design and any materials they choose. 

The most common style of positioner consists of a plastic hook attached to a webbing strap that wraps underneath the vehicle seat.  The plastic hook style positioners often claim to have a steel core with a plastic outer shell. An investigation cut open multiple different brands of plastic hooks and did not find a steel core in any models.

Several common styles of seat belt positioners use a strap that wraps underneath the vehicle seat. This strap is routed around compressible, non-load bearing parts of the vehicle seat, rather than being anchors to hard points in the car like a seat belt. 

We know that the vehicle seat belt will hold in a crash. There is no guarantee that a seat belt positioner will remain in place and remain intact in the same crash.

There has been speculation about what kinds of injuries a pregnant occupant could receive if they are in a crash with a seat belt positioner. The truth is that we do not know what will happen. There are no published case studies, population studies, or crash tests that compare the level of injury between people with and without seat belt positioners. 

Would a pregnancy seat belt positioner reduce the level of injury? Would it increase the level of injury? We could make educated guesses, but we do not know for sure. What we do know is that using a device with this many unknowns is not advisable. 

Some seat belt positioner advertisements claim that their products are "legal" or "approved." Seat belt positioners are only legal in the sense that there is no law against their use. There are no pregnancy seat belt positioners that have been approved by a government body. 

The use of a seat belt positioner modifies the seat belt with a product that is not approved by the seat belt manufacturer. Non-approved devices like seat belt positioners can potentially affect legal liability. If a pregnant occupant is injured by the seat belt, the vehicle and seat belt manufacturers may be able to argue that they are not liable because the belt was not being used as intended. At the same time, if the positioner itself did not fail then the positioner manufacturer may also be able to argue that they are not liable.

Tracking down a positioner manufacturer may also be quite difficult. Many positioners are produced by offshore plastic molding companies and sold by third party distributers. Online retailer listings are often taken down after a few weeks and reposted, making it difficult to find the original purchase listing.