Chapter 18: Trauma and Pregnancy

EPIDEMIOLOGY

Trauma is a major cause of maternal and fetal morbidity and mortality in the United States.^* 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 Although many women with traumatic injury do not have prolonged hospital stays, it is still a major cause of nonobstetric maternal mortality.^2,3 Aside from an already high incidence, there is major cause that maternal trauma is a major health disparity. Analysis using American College of Surgeons National Trauma Data Bank (NTDB) confirmed that although pregnant patients tend to be younger, less severely injured, they were more often black or Hispanic when compared to nonpregnant controls. Twenty percent of pregnant patients tested positive for drugs or alcohol, and one in three involved in motor vehicle crashes (MVCs) did not use or had a misuse of 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.^5,6

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.⁷ Regarding abdominal injuries, one large center reported that 91% were blunt injuries, while 9% had penetrating trauma.⁸

Motor Vehicle Crashes

MVCs 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 2001.⁹ 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.¹⁰ Women hospitalized after MVCs are known to be at risk for adverse pregnancy outcomes, but data suggests that adverse pregnancy outcomes (ie, preterm labor [PTL]) are not quantified by standard risk stratification for the nonpregnant population as risk is increased even after minor injury during pregnancy.¹¹

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.¹² Biomechanical studies confirm that postural sway increases, stance is wider, and perception of balance is decreased in ...