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
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
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
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 late gestation.13 Hospitalizations due to falls are 2.3 times more likely in pregnancy. One report compared 693 pregnant women hospitalized with fall injuries against 2079 pregnant controls. Hospitalization due to fall was seen in 49/100,000 deliveries; 79% occurred in the third trimester, with 11% and 9% in the second and first trimesters, respectively. Fracture was the most common injury (47%), usually involving lower extremities, while 18% had contusions and 17% had sprains. Most injuries were minor. Nonetheless, pregnant women who fell had a 4-fold higher risk for PTL and an 8-fold higher risk for abruption.14
Contrary to popular assumptions, intimate partner violence (IPV) during pregnancy is not rare and crosses in all socioeconomic strata. Assaults during pregnancy typically involve areas of the body covered by the back, chest, and torso or a “1-piece bathing suit.” Estimates vary, but up to 15% to 25% of women receiving prenatal care in public health clinics report IPV. Adolescents appear to be at particular risk, both before and during pregnancy. While whites are more likely to have IPV, black women are the most likely to be murdered. Alcohol and substance abuse play a significant role in IPV for both perpetrators and victims. Overall, pregnant victims of IPV are more likely to receive no prenatal care or delay entry into prenatal care and are as a common reason women choose to terminate a pregnancy.15 IPV during pregnancy is linked with a variety of adverse outcomes. Data from the pregnancy risk assessment monitoring system (PRAMS) survey of 118,579 women in 26 states showed that those reporting IPV in the year prior to pregnancy had higher risks for high BP or edema, vaginal bleeding, severe nausea and vomiting, kidney infection or urinary tract infection (UTI), hospital visits, preterm births (PTB), low birth weight (LBW), and need for neonatal intensive care unit (NICU) care.16 Another cohort study reported on women who experienced violence before or during pregnancy versus women with no prior violence. Overall rates of PTB were similar, but married women who experienced violence had a higher proportion of LBW and preterm infants.17 Obstetric risks related to IPV were also found in a study of 105 women who reported IPV during prenatal care. After controlling for sociodemographics, tobacco, alcohol, drugs, preeclampsia, and diabetes, there remained a 32-fold greater risk for trauma and a 5-fold greater risk for placental abruption.18 A case control study in 10 cities compared 437 gravidas who experienced attempted and/or completed homicide with similarly abused nonpregnant women. Abuse during pregnancy was reported by 23% to 26% attempted and/or completed homicide victims, versus 8% of controls. Five percent of homicide victims were murdered while pregnant. The risk of being a homicide victim was 3 times higher for women abused during pregnancy.19 A study of homicide during pregnancy explored data from the New York Office of the Chief Medical Examiner. The victim and suspect were known to each other in 18 of 27 cases. Of these, 16 were involved in an existing or prior intimate relationship, confirming the strong role of IPV in maternal homicide.20 Universal screening for domestic violence is recommended by professional organizations, such as the American Medical Association (AMA), American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Family Physicians (AAFP). Should a patient indicate that IPV is a concern, assistance is available from the National Domestic Violence Hotline (1-800-799-SAFE). A variety of other local resources may be available in many communities.
National Domestic Violence Toll Free Hotline 1-800-799-7233
ACOG Violence Against Women Resources: www.acog.org/About_ACOG/ACOG_Departments/Violence_Against_Women
National Coalition Against Domestic Violence: http://www.ncadv.org
Blunt abdominal trauma accounts for most cases of maternal trauma, most of which are related to MVCs. Falls, pedestrian injuries, and assaults are other common etiologies. The risk for maternal or fetal complications relates to the gestational age at delivery. The uterus is protected within the pelvis until roughly 12 weeks and then it rises to the level of the umbilicus at 20 weeks. The bladder is displaced upward as the uterus grows, making it an intra-abdominal organ vulnerable to injury. The uterine wall becomes thinner and the relative amount of amniotic fluid decreases with advancing gestation; these changes contribute to the possibility of adverse placental or fetal effects. Potential sequelae of blunt trauma relate to characteristics of the force and size of the uterus, and include placental abruption, uterine rupture, or even direct fetal injury.21
About 9% of maternal abdominal injuries are due to penetrating trauma, with prevalent injuries being gunshot (73%), stabbing (23%), or shotgun (4%). Maternal and fetal risks are related principally to severity of abdominal injury and maternal hypotension. Although maternal risk of mortality (3%-4%) is lower than for nonpregnant women, the risk of fetal injury and death is as high as 73%.8,22 This makes sense, given that the gravid uterus in late pregnancy would absorb much of the energy from projectiles, would displace bowel peripherally, and would prevent vascular injury by occupying the space anterior to the great vessels.
The overall approach for management is similar to that of nonpregnant patients, with penetrating objects left in place until imaging and/or surgical exploration can be affected. In nearly all cases, abdominal exploration is required. However, a selective approach to laparotomy was described in a series of 14 gravidas with penetrating trauma. The authors found that visceral organ injury was more likely if the entry wound was in the upper abdomen, but not when below the uterine fundus. For cases of lower abdominal injuries, observation and wound exploration were considered so long as the fetal status was satisfactory.23 Generally, superficial stab wounds may be observed if confined to the abdominal wall, but laparotomy is required if intraperitoneal bleeding or bowel injury is suspected. Cesarean delivery may be indicated if a viable fetus is in imminent risk of death or if the gravid uterus prohibits exposure to repair maternal injuries.24
*Author of previous edition.
Fractures, dislocations, sprains, and strains were the most common injures affecting pregnant women in one large study. Women whose injuries resulted in delivery during their trauma hospitalization had extremely high odds of maternal death (odds ratio [OR] 69), fetal death (OR 4.7), uterine rupture (OR 43), and placental abruption (OR 9).7
Trauma is the leading cause of nonobstetric maternal deaths, with a wide variety of traumatic injury to those who sustain it: 57% homicide, 9% suicide, 23% gunshot wound, 21% MVCs, 14% stabbing, 14% strangulation, 9% blunt head injury, 7% burns, 5% falls, 5% toxins, and 2% drowning.3 Similarly, New York medical examiner records concluded 39% of deaths in pregnant women were injury-related, with homicide in 63%, suicide in 13%, and 12% due to MVCs.25 Pregnant women actually exhibit lower mortality rates than nonpregnant controls when they are matched for age and equivalent injuries.26
Homicide is an important cause of death among pregnant and postpartum women. Data from the Pregnancy Mortality Surveillance System (1991-1999) were used to review 617 homicides, which corresponded to 1.7/100,000 live births. These represented 8% of all maternal deaths, and 31% of pregnancy-associated injury deaths. Homicide was the second leading cause of maternal injury deaths after MVCs. Risk factors for maternal homicide included age less than 20 years and late/no prenatal care. Firearms were the leading mechanism in more than half of cases. Homicide was 7 times higher for black versus white women.27 A statewide study in North Carolina found similar results, with homicide accounting for 36% of injury-related maternal deaths and nonwhites being at 1.8 times higher risk.28
Suicide is less common than homicide, accounting for 10% of maternal deaths. A history of prior suicide attempt increases the risk sharply and a family history doubles the risk. Other risk markers include adolescence, unmarried status, financial strain, and IPV. Most suicides occur during the first trimester, with intentional overdose as the most common method. Women who commit suicide after birth often make their attempt within the first 2 months and use more violent methods.29
Estimates of fetal death rates after maternal trauma vary. A population-based study in Sweden evaluated traffic, medical, and autopsy registries, and found that MVCs during pregnancy were associated with a perinatal mortality rate of 3.7/100,000.30 Danish women who received medical treatment for an injury at any time during pregnancy were also more likely to have a spontaneous abortion or stillbirth.31 Similar findings were seen in one US study of fetal death certificates from 16 states over a 3-year period. Authors identified 240 fetal deaths due to maternal trauma, or 3.7 per 100,000 live births. MVCs accounted for 82% of cases, with firearms and falls accounting for 6% and 3% of cases, respectively. The highest rate of fetal deaths (9.3 per 100,000) was seen among teens aged 15 to 19 years. Placental injury was cited in 42% of cases, and maternal death also occurred in 11% of cases.32 Other reported risk factors for fetal death include prolonged maternal hypotension or hypoxemia, abruption, uterine rupture, and direct uterine trauma. It has been estimated by one author that the rate of fetal deaths due to MVC exceeds that of infant deaths by 7-fold.9
Specific clinical factors have been shown to be predictors of fetal death after blunt abdominal trauma, including ejection from vehicle, motorcycle or pedestrian collision, maternal death, maternal tachycardia, abnormal fetal heart rate (FHR), lack of restraints, and injury severity score (ISS) greater than 9.33 Timing and severity of maternal injuries may affect the risk for miscarriage or fetal demise as is evident from the review of 376 fetal deaths reported in 2005. As anticipated, severe injuries were associated with a 6-fold increase in odds of fetal demise and prematurity/LBW. The odds of fetal demise after minor injury in the first trimester were increased by a factor of 1.8, and by 1.65 following a second trimester incident.34
Recent data suggest that maternal trauma in early pregnancy increases the risk for structural fetal malformations. The National Birth Defects Prevention Study assessed periconceptional injuries and subsequent of birth defects. Associations were identified between longitudinal limb deficiency, gastroschisis and hypoplastic left heart syndrome (HLHS), and intentional injury. Other congenital heart malformations were increased, including interrupted aortic arch, ASD, pulmonary atresia, and tricuspid atresia, as was anorectal atresia or stenosis. This is cause for concern, and further research is warranted.35
PTL is common among trauma patients beyond 20 weeks (especially after blunt trauma), but episodes resolve spontaneously in many cases. Risk factors most predictive of PTL after blunt abdominal trauma include gestational age more than 35 weeks, assaults, and pedestrian collisions, according to one study.33 However, recent literature suggests PTL may ensue after the initial injury. In one study, a 2-fold increase in PTB and LBW was found after discharge from injury hospitalization. The risk of PTL was higher with increasing injury severity and for injuries prior to 24 weeks.36 Similar findings were reported in a study of 11,817 PTB/LBW deliveries in Tennessee. After adjusting for race, advanced maternal age, smoking, and prior PTB, the authors found a doubling of odds for PTB/LBW in women with severe second- or third-trimester maternal injury. Surprisingly, women with mild injury in the first or second trimester were also 1.2 times more likely to have PTB/LBW than uninjured controls.34 Finally, a study of 582 women from Washington State (1989-2001) evaluated outcomes after severe, mild, or no injury. Over 80% were discharged after their initial injury hospital stay. Those with severe and nonsevere injuries were at increased risk for abruption, cesarean, and fetal death. Surprisingly, uninjured women were also at risk for PTL (relative risk [RR] 7.9) and abruption (RR 6.6) compared with women not involved in collisions.11 Thus, it is important to observe for signs of PTL even beyond the initial trauma, and that ISS does not predict PTL.
The use of tocolytic medications for PTL in injured women is controversial. Although preterm contractions in trauma are often transient, the use of tocolytic therapy to negate preterm delivery has been described. One study evaluated 84 patients after major trauma in late pregnancy; preterm contractions occurred in 28%; and 17 received tocolytic therapy. Five patients responded to one dose of terbutaline, while eight received IV magnesium, and four were given Ritodrine. Overall, 14 of 17 delivered at term.37 In another study, 205 trauma patients were evaluated, of whom 18 had OB complications. Ten developed PTL and received tocolytic medications. All 10 responded initially, but 3 delivered in less than 12 hours due to abruption, and all others delivered prematurely 2 to 7 weeks later.38 Finally, 85 women with blunt abdominal trauma were followed prospectively; 13 delivered preterm. Thirty-one percent who delivered preterm received magnesium, compared to only 7% with term births. There were no differences between groups in terms of clinical factors, but 46% with PTB had complications such as premature labor and/or rupture of membranes (PROM) or abruption, versus 13% delivering at term.39
The benefit of tocolysis after traumatic injury remains unclear. Although there is some evidence that PTL is hastened, the provider must take into account the most likely reasoning for uterine contractions in trauma: hypovolemia and placental abruption. In this setting, it is preferred that appropriate intravenous resuscitation be employed and continuous monitoring be instituted to rule out placental abruption.
Placental abruption complicates 1% of deliveries in the general population. Placental abruption is a serious complications of blunt abdominal trauma, and has been estimated to occur in 7% to 9% after trauma with no or minor injury, but 13% after severe injury.11 Complications due to abruption depend on the severity of placental bleeding and gestational age. Classic signs and symptoms of abruption include vaginal bleeding, painful contractions, and a nonreassuring fetal status with late decelerations. However, the clinical presentation can be subtle, especially in cases of concealed hemorrhage. Trauma-related abruption could be due to shear failure (differences in the elasticity of myometrium and placenta) or tensile failure (coup-contrecoup injury). Risk markers for abruption reported in various clinical studies include low maternal education, nonwhite race, lack of seat belt use, and high-speed collision.21
Women hospitalized after MVC have been shown to be at higher risk for abruption, even when no maternal injury is present. The risk for abruption was 7 times higher for women evaluated due to MVC when compared to those not involved in collisions.11 Although late placental abruptions have been reported in 1% to 2% of patients up to 48 hours after blunt abdominal trauma,40 abruption is usually diagnosed within 2 to 6 hours after trauma. A study of 85 women monitored by electronic fetal monitoring (EFM) for 4 hours after trauma showed there were no episodes of abruption within 24 hours when there were no contractions in any 10-minute interval and there were no symptoms of pain or bleeding.40 Although the optimum duration of observation is unclear, most advise 6 hours of cardiotocography after trauma for women with pregnancies at or beyond viability after trauma without contractions and 24 hours if contractions are present.40,41
Fetomaternal hemorrhage (FMH) occurs when fetal blood enters the maternal circulation. The incidence of FMH is 3 per 1000 births (assuming 30 mL of fetal blood lost). However, the amount of fetal bleeding causing clinically significant fetal risk depends on the loss relative to total fetal blood volume and whether fetal blood loss is acute or chronic. Unfortunately, there are few early clinical signs of fetal anemia due to FMH. Signs of fetal anemia include abnormal FHR pattern (sinusoidal or otherwise nonreassuring), fetal hydrops, fetal atrial fibrillation, decreased fetal movements, or stillbirth.42
The current standard test for FMH is the acid elution test, or the Kleihauer-Betke (KB) test. KB testing involves determining the percentage of red blood cells (RBCs) from maternal blood which stain positive for fetal hemoglobin (HbF). This test is labor intensive, and can underestimate fetal RBCs in late gestation (decreasing HbF content) or may overestimate in those who overproduce HbF (eg, thalassemia, sickle cell). Flow cytometry is another method and is more sensitive and accurate in measuring HbF, but is not available nationally. Flow cytometry is indicated when results from KB testing or standard anti-D are discrepant or if there is maternal/fetal RhD compatibility.43
FMH is strongly associated with PTL and placental abruption. PTL is 20 times more common when KB (+) without other PTL risk factors.44 Other data question whether KB testing is useful in the setting of trauma. In one study, low-risk (atraumatic) women underwent KB testing at the time of Glucola screening. Control KB results were compared to 583 patients with trauma evaluation at comparable gestational ages. Five percent of “low-risk” women had positive KB tests, whereas 2.6% of trauma patients had positive KB tests. These results suggest that a positive KB may not always reflect a pathological FMH.45
The long-term prognosis is guarded for cases of massive FMH, but follow-up data are limited. Among 48 patients with massive FMH (KB ≥40/10,000 or FMH ≥20 mL/kg), there were 6 fetal deaths. PTB and NICU transfer were seen in 19%, and neonatal transfusion in 10%. However, 31 of the infants followed over 8 years displayed no neurological sequelae.46 Most authors continue to advise KB testing in cases of blunt abdominal trauma during pregnancy. If positive, continuous monitoring should be continued and evaluation and noninvasive measures of fetal anemia should be considered.42
Uterine rupture is estimated to occur in 0.7% of all maternal traumas, which represents a 45-fold increase compared with nontrauma uterine ruptures.7 Uterine rupture is thought to involve direct abdominal impact with high force. Most cases appear to involve the fundal region of the uterus, and the fetal prognosis is poor. Case reports suggest that maternal death may be more common than for cases of uterine rupture due to other causes. The extent of injury and clinical presentation are highly variable, but clinical features could include abdominal pain or distension, nonreassuring FHR pattern, and other signs of hypovolemia. Since hemorrhage can be life threatening due to the high uterine blood flow during gestation, laparotomy is always indicated, and hysterectomy may be required if the uterus cannot be repaired satisfactorily.21,24
Direct fetal trauma complicates fewer than 1% of all pregnancies following trauma. Most cases result from serious maternal injury or from penetrating trauma: stabbing and gunshot wounds.21,24 Unusual fetal consequences of trauma include limb-body wall complex, fetal subdural hemorrhage, and fetal CNS damage such as hydrocephalus or cerebral palsy. Case reports describe direct fetal injury and/or long-term sequelae relating to trauma during pregnancy after MVCs, auto versus pedestrian collisions, motorcycle crashes, with or without seat belt use or airbag deployment, with penetrating trauma, and other scenarios.
Treatment of pregnant patients with orthopedic fractures is quite complex. Urgent treatment and resuscitation of the mother provides the best outcome. Emergent fractures that are life threatening deficits should be immediately evaluated and fixed. One study compared 65 women with orthopedic injuries to 990 controls at a Level 1 trauma center. Increased risks for PTD(31% vs 3%), abruption (8% vs 1%), and perinatal mortality (8% vs 1%) were seen in the group with orthopedic injuries.47 Another study of 3292 women with one or more fractures confirmed a sharp increase in maternal mortality (OR 169), as well as abruption and transfusion for those who delivered due to their injury. Women who were discharged undelivered had high rates of delayed complications, with a 46% increase in LBW and a 9-fold increase in thromboembolism. Pelvic fractures had the worst outcomes.48
Pelvic fractures confer a particularly high maternal and fetal risk. Pelvic and acetabular fractures are associated with high maternal mortality (9%) and fetal mortality (35%).49 Maternal mortality was also highest after automobile versus pedestrian collision. Mechanism of injury was important, since vehicular collisions were more strongly associated with fetal loss than falls. Injury severity was important, but fracture classification and type, and trimester did not affect outcomes in that series.49 During maternal evaluation and surgery, imaging with radiation exposure is not contra-indicated; however, efforts for the least amount of radiation exposure should be undertaken.
There are limited data regarding the route of delivery following pelvic fracture. This issue was studied in 31 women with prior pelvic fracture. Among 25 vaginal births in 16 women after healed pelvic ring fractures, 28% had prior surgical treatment for pelvic fracture, and 16% had retained anterior or posterior hardware, including trans-symphyseal plating in 3 patients (12%). In contrast, 13 of the women had 26 cesarean deliveries, with 46% after surgical treatment for their pelvic injury. Although 2 women had elective repeat cesarean, 7 women underwent 12 cesareans resulting from their pelvic fracture. Three women elected cesareans despite their physicians offering trials of labor. Cesarean was not related to age, fracture pattern, treatment type, or residual pelvic displacement. Uncomplicated pregnancies and vaginal deliveries are possible after pelvic fracture. Fracture pattern, minor malalignment, and retained hardware are not an absolute contraindication to trial of labor. However, if there is concern, providers should discuss with orthopedic surgeons and if possible obtain imaging preconceptually to assess pelvic outlet.50
About 7% of women of reproductive age are seen for treatment of major burns, but the exact incidence of burn injury during pregnancy is unknown.51 Most case series come from outside the United States, so there may be significant difference in patient characteristics and treatments. A study of 51 patients from Iran showed that when burned surface area exceeded 40%, maternal and fetal mortality reached nearly 100%. Kerosene ignition was the most common reason for burns, and large burn area and inhalation injury were the most important factors contributing to death.52
Complications from burns include acute respiratory distress syndrome (ARDS), sepsis, organ failure, or death. Types of burn injuries include thermal, electrical, chemical, and radiation. Thermal wounds contain three zones (coagulation, stasis, hyperemia), each with different clinical features. Electrical burns create severe entry/exit wounds, as well as severe injury to deep tissues. Subsequent myonecrosis can lead to liver or kidney dysfunction. Minor burns involve less than 10% of total body surface area (BSA) and are partial thickness injuries. Moderate burns comprise 10% to 19% of BSA, while severe burns involve 20% to 39% and critical burns affect greater than 40% of total BSA. Major burns also include electrical burns, persons with chronic illness or burns of the face or perineum. Early deaths after burns are usually due to respiratory complications. A frequent cause of mortality is inhaled carbon monoxide or cyanide.53
All major burns require aggressive fluid resuscitation with isotonic solution within the first 24 hours (Parkland Formula). Prophylaxis for stress ulcers and thromboembolism should be provided. Infection and sepsis are the greatest risks to life after the first 36 hours, either due to pneumonia or wound infection. Staphylococci are the most common pathogens initially, but after 5 days, gram negative rods such as Pseudomonas predominate so at suspicion of infection broad spectrum antibiotics should be utilized. Wound care, debridement, and infection control practices are proven strategies for optimizing outcome. Early enteral feeding aids many aspects of recovery after burns, with a high caloric intake of 36 kcal/kg/d and protein intake of 1.5 to 2 g/kg/d. Skin substitutes or topical negative pressure (TNP) therapy may stimulate healing. Rehabilitation care is important to restore function and cosmetic appearance. Pain management may include the use of opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), anesthetics, or anxiolytics. Other treatment modalities could include hypnosis, cognitive behavioral therapy (CBT), and visualization.53
General principles of burn management for pregnant women include aggressive fluid resuscitation, supplemental oxygen, low threshold for intubation, and high suspicion for deep vein thrombosis/pulmonary embolism (DVT/PE) or sepsis.46 There are no formal guidelines regarding care of a pregnant woman with burn injuries, but a multidisciplinary approach seems important.51 Decisions regarding fetal monitoring or early delivery for maternal or fetal indications should be made on a case-by-case basis.53
