Incidence

According to some authors, nearly 50% of maternal deaths are related to trauma. From 6%–7% of all pregnancies are complicated by trauma, and 0.4% of the patients require hospitalization for treatment of injuries. In 1995, Weiss reported an epidemiologic 1-year study in which all women of childbearing age who required hospitalization for injuries were screened for pregnancy; of 16,722 women, 761 were identified (4.6%) as being pregnant. The actual number of injured pregnant women is underestimated as many of them are unreported, especially with injuries resulting from domestic violence.

Mechanism of Injury

Motor vehicle collisions are the most common causes of injury during pregnancy. As the pregnancy progresses, the shift in the woman’s center of gravity and diminished agility can result in falls and accidental injuries. Other common causes of injury include automobile–pedestrian collisions and firearm injuries. Younger women are at higher risk for injury during pregnancy, with a mean maternal age of 25 years.

Young pregnant women are also at high risk for injuries resulting from battery. It has been reported that 10%–30% of women are abused during pregnancy, and 5% of cases involving abuse result in fetal death. Of injured pregnant patients, 17% experience intentional trauma and 60% suffer repeated episodes of domestic violence. Physical abuse is suspected when the injuries are located proximally and in the midline, rather than distally, and trauma is evident to the neck, breast, face, upper arms, and lateral thighs, as well as with bizarre injuries such as cigarette burns or bites.

Diagnosis

Care is undertaken with attention to both mother and fetus. Uterine blood flow lacks autoregulation and is related directly to maternal blood pressure; consequently, treatment priorities are the same as for the nonpregnant trauma patient, as the best initial treatment for the fetus is the optimal resuscitation of the mother. A thorough physical exam complemented by imaging studies is necessary to identify some of the unique problems that might be present in any pregnant patient, including blunt or penetrating injury to the uterus, placental abruption, amniotic fluid embolism, isoimmunization, or premature rupture of membranes.

Hospital Care

Primary survey includes assessment of airway, breathing, and circulation (ABCs), including volume replacement and hemorrhage control. Secondary survey includes the obstetrical history, physical examination, and evaluation and monitoring of the fetus. The history should include the date of the last menstrual cycle, expected date of delivery, and any problems or complications of the current and previous pregnancies such as preterm labor or placental abruption. Comorbidities such as pregnancy-induced hypertension and diabetes mellitus should also be documented.

The abdominal examination is critically important, as is a determination of uterine size, which provides an approximation of gestational age and fetal maturity. A discrepancy between dates and uterine size suggests uterine hemorrhage or rupture. Uterine rupture is suspected with peritoneal signs, abdominal palpation of fetal parts due to extrauterine location, and inability to palpate the uterine fundus. However, as the uterus enlarges, it displaces the intestines upward and laterally, stretching the peritoneum and making the abdominal physical examination unreliable.

Determination of gestational age is particularly important because this will guide the decision for a premature delivery if indicated. Most institutions will accept a 24–26 week pregnancy as viable, with a probability of survival ranging from 20%–70%. Radiographic estimation of gestational age is bound to an error of 1–2 weeks. Unless the date of the conception is known exactly, gestational age is particularly difficult to determine. A good rule of thumb is to consider patients with a uterus halfway between the umbilicus and the costal margin as having a viable pregnancy (Figure 1). An algorithm for initial maternal and fetal assessment is presented in Figure 2.

Figure 1 Computed tomography scan showing pregnant uterus above the level of umbilicus indicating a viable fetus.

Figure 2 Algorithm for initial maternal and fetal assessment. OB, Obstetrics; US, ultrasound; DPL, diagnostic peritoneal lavage; C-section, cesarean section.

(Adapted from Knudson MM, Rozycki GS, Paquin MM: Reproductive system trauma. In Moore EE, Feliciano DV, Mattox KL, editors: Trauma, 5th ed. New York, McGraw-Hill, 2004, pp. 851–875.)

Physical evaluation of the pregnant patient must be directed to the detection of the following six pregnancy-related acute conditions.

Vaginal bleeding

This is an ominous sign that suggests premature cervical dilation, early labor, placental abruption, or placenta previa. Placental abruption after trauma occurs in 2%–4% of minor accidents and in up to 50% of major injuries. Maternal mortality from abruption is less than 1%, but fetal death ranges from 20% to 35%. Both fetal heart monitoring and sonographic evaluation should be used to investigate the possibility of abruption that most frequently becomes evident within several hours after trauma.

Ruptured membranes

In addition to increased risk of infection, prolapse of the umbilical cord can occur, resulting in compression of the umbilical vein and arteries.

Bulging perineum

This is caused most commonly by pressure from extrauterine location of fetal parts.

Presence and patterns of contractions

Direct or indirect trauma to the myometrium may result in release of arachidonic acid that can cause uterine contractions. Although most contractions will cease spontaneously, preparation for a premature delivery should be made.

Abnormal fetal heart rate and rhythm

An abnormal fetal heart rate may be the first indication of a major disruption in fetal homeostasis. During trauma resuscitation, evaluation of the fetus should begin with auscultation of heart tones and continuous electronic fetal heart rate monitoring (EFM). Any viable fetus of 24 or more weeks gestation requires monitoring after trauma. Cardiotocographic monitoring should be started in the resuscitation room and continued for a minimum of 4 hours; a minimum of 24 hours is recommended for patients with frequent uterine activity (more than six contractions per hour), abdominal or uterine tenderness, ruptured membranes, vaginal bleeding, or hypotension.

Fetomaternal hemorrhage

Fetomaternal hemorrhage (FMH) is the transplacental hemorrhage of fetal blood into the normally separate maternal circulation and occurs in 8%–30% of patients with trauma during pregnancy. The severity of injury and the gestational age have no correlation with the frequency and volume of FMH. The Kleihauer-Betke (KB) test is used after maternal injury to identify fetal blood in the maternal circulation. The ratio of fetal to maternal cells is recorded, allowing calculation of the volume of fetal blood leaked to the maternal circulation. Complications of FMH include Rh sensitization in the mother, fetal anemia, fetal paroxysmal atrial tachycardia, and fetal death from exsanguination. As the volume of FMH sufficient to sensitize most Rh-negative women is well below the 5-ml sensitivity level of the typical laboratory’s KB test, all Rh-negative mothers who present with a history of abdominal trauma should receive one 300-mcg prophylactic dose of Rh immune globulin (anti-D immunoglobulin; Rhogam) within 72 hours of the traumatic event. An additional 300 mcg of Rh immune globulin should be given for every 30 ml of fetal blood found in maternal circulation. Only 3.1% of major trauma cases require more than one 300-mcg Rh immune globulin dose. The KB test is probably unnecessary before 16 weeks gestation because the fetal blood volume is below 30 ml at this gestational age.

Radiographic Examination

There are three phases of radiation damage related to gestational age of the fetus. Before 3 weeks of gestation, during preimplantation and early implantation, exposure to radiation can result in death of the embryo. Between 3 and 16 weeks of gestation, during organogenesis, radiation can damage the developing fetal tube, resulting in anomalies in the central nervous system. After 16 weeks, neurologic defects are the most common complication. Prenatal radiation exposure may be associated with certain childhood cancers.

Although there is existing concern about radiation exposure during pregnancy, in most instances the benefits outweigh the risks. It is generally believed that exposure of the fetus to less than 5–10 rad causes no significant increase in the risk of congenital malformations, intrauterine growth retardation, or miscarriage. Radiation doses from common imaging studies are shown in Table 2. All indicated radiographic studies should be performed, as for nonpregnant patients (Figure 3). It is obvious that unnecessary duplication of studies should be avoided.

Table 2 Radiation Doses from Plain Radiographs and CT

Plain anteroposterior chest x-ray	<0.005 rad
Pelvic x-ray	<0.4 rad
CT scan of head (1-cm cuts)	0.05 rad
CT scan of upper abdomen (20 1-cm cuts)	3.0 rad
CT scan of lower abdomen (10 1-cm cuts)	3.0–9.0 rad

CT, Computed tomography.

Figure 3 Pelvic x-ray of a pregnant patient after blunt trauma. Vertebrae and other parts of the fetus can be seen.

Abdominal Evaluation

Evaluation of the abdomen in the pregnant patient may be challenging. Superior displacement of the viscera by the expanding uterus changes the anatomical relation of the intra-abdominal organs (Figure 4). Special attention is needed for patients with rib or pelvic fractures, unexplained hypotension, blood loss, hematuria, or altered sensorium caused by drugs, alcohol, or brain injury.

Figure 4 Exploratory laparotomy after motor vehicle collision. Gravid uterus displacing viscera.

Focused abdominal sonography for trauma (FAST) has a major role in the abdominal evaluation because it provides rapid detection of intra-abdominal and pericardial fluid in the mother as well as quick assessment of fetal condition. In the hemodynamically normal patient, abdominal CT scanning can also be done safely to evaluate both mother and fetus. If CT scan is necessary, both oral and intravenous contrast media should be administered as needed. The main drawback of a diagnostic peritoneal lavage (DPL) is its invasiveness, although the procedure can be done safely and has the same sensitivity as in the nonpregnant patient. DPL should be performed above the umbilicus using an open technique.

The American Association for the Surgery of Trauma (AAST) Organ Injury Scale for gravid uterus is shown in Table 3.

Table 3 AAST-OIS for Gravid Uterus

Grade	Injury Description	AIS-90 Score
I	Hematoma or contusion without placental abruption	2
II	Superficial laceration <1 cm in depth or partial placental abruption <25%	3
III	Deep laceration 1 cm in depth in second trimester or placental abruption 25% but <50%; deep laceration in third trimester	3–4
IV	Laceration extending to the uterine artery; deep laceration 1 cm with 50% placental abruption	4
V	Uterine rupture in second or third trimester; complete placental abruption	4–5

Surgical Treatment

Penetrating Injury

As the uterus grows and expands out of the pelvis, it becomes an easier target for penetrating trauma. The thick density of its musculature allows the uterus to absorb energy from low-velocity penetrating injuries; maternal death is very uncommon except for injuries in the upper abdomen, which usually produce severe maternal damage. Gunshot wounds cause fetal injuries in 60%–70% of cases, with fetal death in 40%–65%. If the bullet has penetrated the uterus and the fetus is viable, cesarean section is indicated. Indications for C-section at celiotomy are summarized in Table 4.

Table 4 Indications for C-Section during Laparotomy for Trauma

Maternal shock Threat to life from exsanguinations from any cause Mechanical limitation for maternal repair Irreparable uterine injury Fetal distress in viable fetus Unstable thoracolumbar spine injury Pregnancy near term Maternal death

Perimortem C-section is indicated in the case of maternal death if the fetus is viable (24 weeks). Timing is critical, as the probability of fetal survival is excellent when delivery occurs within 5 minutes or less of maternal demise. As the time increases, the chance of survival diminishes. In the rare situation where the mother is declared brain dead but maintains good vital signs, the fetus can be allowed to mature before delivery (Figure 5).

Figure 5 Intracranial hemorrhage (right panel) in an 18-week pregnant patient declared brain dead. As the fetus was not viable (left panel), the patient’s family agreed to organ donation.

When performing an emergency C-section on a trauma patient, instead of the commonly used transverse incision, a vertical incision through all the layers into the uterus is safer and faster. This incision avoids injury to the uterine vessels, which enter the uterus from both sides.

Between gestational age 24–32 weeks, open cardiac massage (OCM) without aortic cross clamping should be seriously considered before an emergency C-section is performed. If OCM proves successful, the delivery may be delayed so that chances of postnatal survival improve. A proposed algorithm for emergency C-section after trauma is presented in Figure 6.

Figure 6 Algorithm for emergency cesarean section after trauma. C-section, Cesarean section; CPR, cardiopulmonary resuscitation.

(Adapted from Morris JA Jr, Rosenbower TJ, Jurkovich GJ, et al: Infant survival after cesarean section for trauma. Ann Surg 223:481–488, 1996.)

Morbidity and Mortality

Trauma has become the most frequent cause of maternal death in the United States. Older reports attributed 80% maternal mortality to amniotic fluid embolism, which together with pulmonary thromboembolism was cited as the leading cause of maternal mortality. In contrast to declining maternal mortality from infection, hemorrhage, hypertension, and thromboembolism, accidental deaths during pregnancy have risen steadily. According to the latest statistics, as many as 36% of maternal deaths are caused by penetrating trauma. While overall maternal mortality from abdominal gunshot wounds is low (3.9%), fetal mortality ranges between 40% and 70%. Risk factors associated with poor fetal outcome are listed in Table 5.

Table 5 Predictors of Fetal Outcome

Conclusions

Trauma has become the leading cause of death in women aged 34 and younger, including pregnant patients. Pathophysiologic changes in pregnancy affect all aspects of traumatic injury and require detailed assessment and meticulous management.

Incidence

The incidence of injuries to the female genitalia is largely unknown. Most information on the subject comes from isolated case reports or small series of patients. Vaginal lacerations complicate approximately 3.5% of pelvic fractures in female patients. Urethral and bladder injuries are also commonly present.

Mechanism of Injury

Blunt injuries involving the female genitalia are most frequently associated with pelvic fractures. Injuries to the external genitalia can also be the result of straddle injuries or accidental penetration. Water skiing, gymnastics, and bicycling accidents have been reported as the causes of blunt trauma to the lower genitalia. Penetrating injuries are almost exclusively responsible for injuries to the upper genital organs, although several reports of blunt trauma to normal ovaries and uterus have been reported.

Many of the injuries to the external genital organs are the result of violent acts in pregnant as well as nonpregnant women. This possibility should be always be considered, especially when the mechanism of injury is unclear. If sexual assault has occurred, informed consent for the remainder of the assessment must be obtained.

Domestic violence crosses lines of ethnicity/race, age, national origin, sexual orientation, religion, and/or socioeconomic status, although an overwhelming majority of the victims in heterosexual relationships are women. Typically, battery tends to occur as a pattern of violence rather than a one-time event. Physicians treating trauma victims should able to recognize the signs of domestic violence, refer patients to appropriate agencies, and provide social and other support.

Diagnosis

Initial assessment and resuscitation are performed as for any trauma patient. The secondary survey should include a detailed physical examination of the perineum. Examination under anesthesia may be needed for patients with severe pain or active bleeding. A complete examination should include bimanual palpation and speculum examinations of vagina and anorectum. Some authors recommend anesthesia for all patients with perineal trauma in order to evaluate the extent of the injury.

Intra-abdominal genital injuries are usually diagnosed at laparotomy for associated injuries. As blunt injury is more common with pathologically enlarged internal genitalia in the nongravid patient, CT scan of the abdomen or DPL may aid the diagnosis, although the latter is very rarely used. Detailed grading of gynecologic injuries is presented in Tables 6 through 10.

Table 6 AAST-OIS for Gynecologic Injuries: Vagina

American Association for the Surgery of Trauma (AAST).

Modified from Moore EE, Jurkovich GJ, Knudson MM, et al: Organ injury scaling VI: extrahepatic biliary, esophagus, stomach, vulva, vagina, uterus (nonpregnant), uterus (pregnant), fallopian tube, and ovary. J Trauma 39(6):1069–1070, 1995.

Table 7 AAST-OIS for Gynecologic Injuries: Vulva

American Association for the Surgery of Trauma (AAST).

Modified from Moore EE, Jurkovich GJ, Knudson MM, et al: Organ injury scaling VI: extrahepatic biliary, esophagus, stomach, vulva, vagina, uterus (nonpregnant), uterus (pregnant), fallopian tube, and ovary. J Trauma 39(6):1069–1070, 1995.

Table 8 AAST-OIS for Gynecologic Injuries: Nongravid Uterus

American Association for the Surgery of Trauma (AAST).

Modified from Moore EE, Jurkovich GJ, Knudson MM, et al: Organ injury scaling VI: extrahepatic biliary, esophagus, stomach, vulva, vagina, uterus (nonpregnant), uterus (pregnant), fallopian tube, and ovary. J Trauma 39(6):1069–1070, 1995

Table 9 AAST-OIS for Gynecologic Injuries: Fallopian Tube

American Association for the Surgery of Trauma (AAST).

Modified from Moore EE, Jurkovich GJ, Knudson MM, et al: Organ injury scaling VI: extrahepatic biliary, esophagus, stomach, vulva, vagina, uterus (nonpregnant), uterus (pregnant), fallopian tube, and ovary. J Trauma 39(6):1069–1070, 1995

Table 10 AAST-OIS for Gynecologic Injuries: Ovary

American Association for the Surgery of Trauma (AAST).

Modified from Moore EE, Jurkovich GJ, Knudson MM, et al: Organ injury scaling VI: extrahepatic biliary, esophagus, stomach, vulva, vagina, uterus (nonpregnant), uterus (pregnant), fallopian tube, and ovary. J Trauma 39(6):1069–1070, 1995.

Surgical Management

Isolated perineal lacerations should be repaired after appropriate irrigation and debridement with or without placement of drains. Large perineal hematomas require incision and drainage because of the high associated incidence of infection and sepsis. Vulvar lacerations may be closed primarily with absorbable sutures.

Repair of vaginal and cervical lacerations may be challenging because of the abundant blood supply. Absorbable sutures including the mucosal and submucosal layers are commonly used. These injuries must be diagnosed promptly in patients with pelvic fractures, as any delay can result in sepsis and death.

Injuries to the uterus are repaired in two layers using slowly absorbable running or interrupted figure-of-eight sutures. Hysterectomy for trauma is extremely rare and is only needed in extreme cases of massive destruction or exsanguinating hemorrhage. Injuries to the fallopian tubes and ovaries are also managed by either primary repair or excision according to injury severity. Vaginal packing with antibiotics is frequently used for 24 hours after procedures involving the vagina, cervix, or uterus.

Morbidity and Mortality

Morbidity is primarily determined by the associated injuries. Profuse bleeding from the perineal wounds as well as vagina, cervix, and uterus may be the cause of hemorrhagic shock. These wounds may be difficult to control. Missed perineal injuries in association with pelvic fracture may be fatal. Long-term complications include sexual dysfunction and infertility.

Conclusions

Injuries to the nongravid uterus as well as female genital organs are rare and should be suspected in all assault victims and all patients with direct perineal trauma, pelvic fractures, or penetrating injury to the pelvis. Thorough physical examination, preferably in the operating room, with prompt surgical treatment improves the outcome of these potentially challenging injuries.