Seat Belts

There is abundant evidence that demonstrates that wearing a seat belt in the recommended manner leads to a decrease in adverse fetal and maternal outcomes after a motor vehicle collision. 

• A study of 25,168 pregnant drivers involved in MVCs in North Carolina found that unbelted women experienced a higher rate of adverse fetal outcomes, particularly fetal loss. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3859429/

• A series of crash tests specifically designed to look at the area of placental abruption found that negative fetal outcome was not likely with a correctly positioned seat belt. https://www.mdpi.com/1660-4601/19/21/13905

• An analysis of detailed crash reports in Michigan noted adverse fetal outcomes for 29% of properly belted subjects, 50% of improperly belted subjects, and 80% of unbelted subjects. https://pubmed.ncbi.nlm.nih.gov/18395036/

• A study of 8,938 pregnant vehicle occupants in Utah found that unbelted occupants were 1.3 times more likely to have a low birthweight infant, twice as likely to experience excessive maternal bleeding, and 2.8 times more likely to experience a fetal loss than seat belted occupants. https://pubmed.ncbi.nlm.nih.gov/12907100/

• The same study also concluded that pregnant vehicle occupants who were wearing a seat belt did not have a significantly higher risk of an adverse fetal outcome than a pregnant person who was not in a crash at all during their pregnancy. https://pubmed.ncbi.nlm.nih.gov/12907100/

• A series of front- and rear-impact crash tests using a dummy designed to simulate a 30-week pregnant occupant found a 20% probability of adverse fetal outcome when the dummy was belted and a 60% probability of adverse fetal outcome when unbelted. https://pubmed.ncbi.nlm.nih.gov/20435292/

• A review of Duke Trauma Registry patients found significantly higher rates of perinatal death among unbelted occupants. Additionally, it found that 73% of unbelted women complained of abdominal pain, versus 54% of belted women. And 25% of unbelted women required non-obstetric surgery following an MVC, compared to 7% of belted women. https://pubmed.ncbi.nlm.nih.gov/23439323/

• A study of 680 pregnant trauma patients from the National Trauma Data Bank found that unbelted pregnant patients were more severely injured, needed emergent surgery more frequently, and had longer hospital stays than belted pregnant patients. https://pubmed.ncbi.nlm.nih.gov/32422432/

• A series of crash simulations comparing unbelted, lap belt only, and lap and shoulder belt concluded that the lap and shoulder belt provided the greatest protection. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3217485/

• The first crash tests completed with a specially designed pregnant crash test dummy recorded the lowest force and acceleration readings when the seat belt was worn in the recommended manner. https://pubmed.ncbi.nlm.nih.gov/8885759/

• A review of 188 pregnant trauma patients at a level 1 trauma center found that every one of the maternal fatalities in the hospital’s records were not wearing a seat belt at the time of the collision. https://pubmed.ncbi.nlm.nih.gov/17426561/

• Crash simulations using a highly detailed representation of a pregnant occupant and fetus to compare belted and unbelted occupants found that an unrestrained pregnant occupant had the highest uterine strain and risk of adverse fetal outcome. https://pubmed.ncbi.nlm.nih.gov/14520231/

• An extremely detailed review of 120 MVCs involving pregnant occupants found that almost all cases of direct fetal injury, uterine injury, or maternal death were not wearing a seat belt. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3400205/

• A different review of case studies concluded that improperly restrained pregnant occupants have an increased risk of adverse fetal outcomes, even in low severity crashes. https://pubmed.ncbi.nlm.nih.gov/11558095/

• Using national data of pregnant occupants in MVCs, it was noted that 96.7% of seat belt-related injuries were categorized as minor injuries. https://pubmed.ncbi.nlm.nih.gov/25463946/

Since their advent airbags in passenger vehicles have reduced injuries and saved lives. Over the years the designs have been refined and improved. While there is less research information available for airbags, the evidence shows that airbags are effective in reducing injury for pregnant vehicle occupants.

• In a series of 30 cases at two major hospitals where a pregnant vehicle occupant was involved in an MVC with airbag deployment only one of the 30 patients experienced a fetal loss. https://pubmed.ncbi.nlm.nih.gov/16967003/

• Another set of cases from a different hospital found that airbag deployment did not appear to increase risk to pregnancy. https://pubmed.ncbi.nlm.nih.gov/8841272/

• A series of crash tests using dummies designed to simulate a pregnant occupant found that a three-point seat belt coupled with an airbag provided superior protection to the three-point belt alone. https://pubmed.ncbi.nlm.nih.gov/14520231/

• A follow-up series of crash tests using computer simulations designed to recreate a pregnant occupant confirmed that a three-point seat belt paired with an airbag led to the lowest amounts of uterine strain recoded in the testing. https://pubmed.ncbi.nlm.nih.gov/14520231/

• A study of 25,168 pregnant drivers involved in MVCs in North Carolina found that pregnant occupants in vehicles without airbags experienced higher rates of placental abruption and preterm birth than pregnant occupants in vehicles equipped with airbags. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3859429/

• Using national data of pregnant occupants in MVCs, it was noted that 98.9% of seat belt-related injuries were categorized as minor injuries. Additionally, 58.1% of the pregnant occupants who were injured by the airbag were unbelted at the time of the collision. https://pubmed.ncbi.nlm.nih.gov/25463946/