Characteristics of pregnant women in motor vehicle crashes.

OBJECTIVES: Motor vehicle crashes are the leading cause of hospitalized trauma during pregnancy. Maternal injury puts the fetus at great risk, yet little is known about the incidence, risks, and characteristics of pregnant women in crashes. SETTING AND METHODS: Police reported crashes were analyzed from the National Automotive Sampling System Crashworthiness Data System. Since 1995, this system recorded pregnancy/trimester status. Pregnant and non-pregnant women 15-39 years of age were compared by age, driver status, seat belt use, and treatment. Belt use and seating position were examined by trimester.
RESULTS: There were 427 pregnant occupants identified (weighted n=32 810, 2.6%, SE 12 585, rate 13/1000 person years). The mean age was 24.9 compared with 24.8 years (pregnant v non-pregnant). Cases were distributed by trimester as follows: first 29.8%, second 36.4%, and third 33.8%. Pregnant women were drivers 70% of the time compared with 71% for non-pregnant women. No belt use was 14% compared with 13% (pregnant v non-pregnant). Mean injury severity was lower for pregnant women but they were more likely to transported or hospitalized. Improper belt use decreased after the first trimester and there was little change in driver proportion by trimester. Third trimester hospitalization rates increased.
CONCLUSIONS: Pregnant occupants in crashes have similar profiles of restraint use, driver status, and seat position but different treatment indicators compared to non-pregnant occupants. Trimester status has relatively little impact on crash risk, seating position or restraint use. Undercounting of pregnant cases was possible, even so, 1% of all births were reported to be involved in utero in crashes. Little research has focused on developmental outcomes to infants and children previously involved in exposure to these crashes.