What is the recommended course of action for a pregnant woman who has experienced trauma?

Management of Pregnant Women Following Trauma

All pregnant women beyond 20 weeks gestation who experience trauma—even minor trauma—require systematic obstetrical examination with fetal heart rate monitoring for at least 4-6 hours, as trauma significantly increases risks of preterm birth, fetal distress, placental abruption, and fetal death. 1, 2

Initial Maternal Resuscitation (Priority #1)

The mother must be stabilized first, as optimal fetal outcome depends entirely on maternal survival and hemodynamic stability. 2, 3

Airway and Breathing

• Consider early intubation if airway compromise is suspected, as pregnant women have increased aspiration risk due to delayed gastric emptying and decreased lower esophageal sphincter tone. 2, 3
• Insert a nasogastric tube in semiconscious or unconscious patients to prevent aspiration of acidic gastric contents. 2
• Maintain maternal oxygen saturation >95% to ensure adequate fetal oxygenation, as the fetus is extremely sensitive to maternal hypoxemia. 2
• Monitor for respiratory failure carefully, as normal PaCO2 in a pregnant trauma patient may indicate impending respiratory collapse (pregnant women normally hyperventilate with PaCO2 around 30 mmHg). 3
• If thoracostomy tube placement is needed, insert it 1-2 intercostal spaces higher than usual due to diaphragm elevation. 2

Circulation

• Establish two large-bore (14-16 gauge) IV lines immediately in seriously injured pregnant patients. 2
• After mid-pregnancy, manually displace the gravid uterus off the inferior vena cava or use left lateral tilt to increase venous return and cardiac output—this is critical as supine positioning can reduce cardiac output by 30%. 2, 1
• When using left lateral tilt, secure the spinal cord appropriately to prevent secondary injury. 2
• Transfuse O-negative blood in Rh-negative mothers until cross-matched blood is available to prevent Rh alloimmunization. 2
• Use vasopressors only for intractable hypotension unresponsive to fluid resuscitation, as they adversely affect uteroplacental perfusion. 2
• Do not inflate the abdominal portion of military anti-shock trousers, as this reduces placental perfusion. 2

Imaging—Do Not Delay for Pregnancy

Perform all medically indicated radiographic studies including CT scans without delay or deferral due to fetal radiation concerns. 2, 1

• The risk-benefit balance of diagnostic imaging strongly favors maternal diagnosis and treatment. 1
• Fetal radiation exposure from typical trauma CT imaging is well below thresholds for adverse effects (<50 mGy). 1
• Ultrasound (FAST exam) is specific but not sensitive for intraabdominal hemorrhage—a negative FAST does not exclude significant injury. 1, 2
• CT with IV contrast is preferred over non-contrast CT for detecting visceral organ and vascular injuries. 1
• Gadolinium-based contrast agents can be used when maternal benefit outweighs potential fetal risks. 2

Fetal Assessment (After Maternal Stabilization)

Timing and Duration of Monitoring

All pregnant trauma patients ≥23 weeks gestation require continuous electronic fetal monitoring for at least 4-6 hours, even after minor trauma. 1, 2, 4

Extend monitoring to 24 hours if any of these high-risk features are present: 1, 2

• Uterine tenderness or significant abdominal pain
• Vaginal bleeding
• Sustained contractions (>1 per 10 minutes)
• Rupture of membranes
• Atypical or abnormal fetal heart rate pattern
• High-risk mechanism of injury (motor vehicle accident, assault, fall from height)
• Serum fibrinogen <200 mg/dL

If monitoring is normal and early warning symptoms are absent after 4-6 hours, the patient may be discharged with precautions, as the negative predictive value for adverse outcomes is 100%. 5

Obstetrical Ultrasound

• Perform urgent obstetrical ultrasound when gestational age is undetermined and delivery may be needed. 2
• All patients admitted for >4 hours of monitoring should have obstetrical ultrasound prior to discharge. 2
• Ultrasound is insensitive for placental abruption—do not delay management of suspected abruption waiting for ultrasound confirmation. 2

Laboratory Testing

Essential Tests

• Routine trauma labs plus coagulation panel including fibrinogen in all pregnant trauma patients. 2
• Fibrinogen <200 mg/dL is a high-risk marker requiring extended monitoring. 1

Rh Status Management

All Rh-negative pregnant trauma patients must receive anti-D immunoglobulin. 2, 4

• Perform Kleihauer-Betke testing in Rh-negative patients to quantify maternal-fetal hemorrhage and determine if additional doses of anti-D immunoglobulin are needed beyond the standard 300 mcg dose. 2, 4
• Do not perform Kleihauer-Betke testing in Rh-positive women, as it does not affect management or predict adverse outcomes. 5

Triage and Transfer Decisions

Transfer to labor and delivery unit when: 2

• Injuries are neither life- nor limb-threatening AND
• Fetus is viable (≥23 weeks gestation)

Transfer to trauma unit/emergency room when: 2

• Major injuries are present (regardless of gestational age)
• Fetus is <23 weeks or non-viable
• Severity of injury is undetermined

Maintain low threshold for transfer to tertiary care center, as even isolated minor injuries correlate with adverse maternal and fetal outcomes. 3

High-Risk Complications Requiring Urgent Obstetrical Consultation

Obtain urgent obstetrical consultation immediately for: 2

• Suspected uterine contractions in viable pregnancy (≥23 weeks)
• Suspected placental abruption
• Suspected traumatic uterine rupture
• Vaginal bleeding at ≥23 weeks (defer speculum/digital exam until placenta previa excluded by ultrasound)

Placental Abruption

• Occurs in 1-6% of pregnant trauma patients. 5, 3
• Clinical signs (vaginal bleeding, uterine tenderness, contractions, abnormal fetal heart rate) are more reliable than ultrasound for diagnosis. 2
• Do not delay management waiting for ultrasound confirmation. 2

Perimortem Cesarean Section

In maternal cardiac arrest with viable pregnancy (≥23 weeks), perform cesarean section within 4 minutes of arrest onset to aid maternal resuscitation and fetal salvage. 1, 2, 4

• Maternal survival has been reported up to 15 minutes after cardiac arrest onset. 1
• Neonatal survival has been documented with delivery up to 30 minutes after maternal cardiac arrest. 1
• Summon resources for perimortem cesarean delivery immediately upon recognizing cardiac arrest in pregnant women with fundal height at or above the umbilicus. 1

Trauma-Specific Risks by Mechanism

Motor Vehicle Accidents (54.6% of pregnancy trauma)

• Highest risk throughout all gestational ages. 5
• Associated with 8 of 14 preventable perinatal deaths in one large series. 5
• Emphasize proper seatbelt use at all prenatal visits: lap belt below the uterus, shoulder belt between breasts and to the side of the uterus. 2

Domestic Violence/Assault (22.3% of pregnancy trauma)

• Most frequent before 18 weeks gestation. 5
• Screen every trauma patient specifically for intimate partner violence. 2
• Document fetal well-being carefully for legal purposes. 2
• Associated with 4 of 14 preventable perinatal deaths. 5

Falls (21.8% of pregnancy trauma)

• Most common between 20-30 weeks gestation as center of gravity shifts. 5

Common Pitfalls to Avoid

• Do not withhold indicated CT imaging due to radiation concerns—fetal radiation risk is minimal compared to maternal diagnostic benefit. 1, 2
• Do not rely on ultrasound to exclude placental abruption—clinical findings are more sensitive. 2
• Do not perform Kleihauer-Betke testing in Rh-positive women—it does not predict outcomes or change management. 5
• Do not discharge patients with viable pregnancies without at least 4 hours of fetal monitoring, even after seemingly minor trauma. 1, 2
• Do not delay perimortem cesarean section beyond 4 minutes in maternal cardiac arrest with viable pregnancy. 1, 2
• Do not forget tetanus vaccination when indicated—it is safe in pregnancy. 2