Chapter 18: Trauma and Pregnancy

EPIDEMIOLOGY

Trauma is a major cause of maternal and fetal morbidity and mortality. The incidence of trauma during pregnancy has been estimated to be 3% to 8%. In 2002, there were 16,982 injury hospitalizations of pregnant women in the United States, which corresponds to 4.1 per 1000 deliveries.¹ However, many more women seeking care for injuries do not require inpatient care. A study of 295 women with injuries during 2001 to 2005 showed that 52% were discharged from the emergency department (ED), and only 18% were admitted to the trauma service.² In one study, 1 in 7 pregnant women sought care for injury in Massachusetts during 2002 to 2003. For some subgroups, the rate was as high as 1 in 4.³ Analysis using American College of Surgeons National Trauma Data Bank (NTDB) confirmed that pregnant patients tend to be younger, less severely injured, and more often black or Hispanic when compared to nonpregnant controls. Twenty per cent of pregnant patients tested positive for drugs or alcohol, and 1 in 3 involved in motor vehicle crashes (MVCs) did not use seat belts.⁴ Other studies agree that trauma is more common among adolescents, black women, those with public insurance, less than high school education, substance abuse, or lack of safety restraints.^3,5

Types of Injury

The most common types of trauma during pregnancy include MVCs (48%), falls (25%), and assaults (17%). Intentional injuries (homicide/suicide), gunshot wounds, burns, and poisonings each account for fewer than 5% of cases.⁶ Regarding abdominal injuries, one large center reported that 91% were blunt injuries, while 9% had penetrating trauma.⁷

Motor Vehicle Crashes

Motor vehicle crashes (MVC) comprise at least two-thirds of traumas during pregnancy, a fact that is not surprising, since the average number of miles driven annually by women of reproductive age increased from 3721 to 8258 between 1975 and 2001.⁸ A study of 427 pregnant women in MVCs showed that maternal age was similar to that for nonpregnant women; cases were distributed evenly across trimesters. Seventy percent of pregnant women in crashes were drivers, 14% of which were unrestrained, rates similar to nonpregnant women. Mean injury severity was generally lower for pregnancy, but pregnant women were more likely to be transported.⁹ Women hospitalized after MVCs are known to be at risk for adverse pregnancy outcomes, but recent data suggest the risk is increased even after minor collision during pregnancy.¹⁰

Injury Due to Fall

Posture is stable in the first trimester, but destabilizes in subsequent trimester and for at least 6 to 8 weeks postpartum. In one study of static postural balance, 25% of pregnant women reported falling within the preceding 3 months, whereas no control subjects had fallen in the preceding year.¹¹ Biomechanical studies confirm that postural sway increases, stance is wider, and perception of ...