Trauma in pregnancy

Background

• Concern for trauma, premature labor, and abruption
• Viable = >23-24wk (~fundus above umbilicus)
• nl FHR = 110-160 beats/min
• The leading cause of death in women during their reproductive years
• The leading non-obstetric cause of death and disability in pregnant women
• Trauma or accidental injury complicates up to 7% of all pregnancies
• For maternal vitals see Maternal Vitals and Labs in Pregnancy

Risk Factors for Severity (ATLS)

• Maternal heart rate > 100
• Injury Severity Score > 9
• Evidence of placental abruption
• Fetal heart rate > 160 or <120
• Ejection during a motor vehicle crash
• Motorcycle or pedestrian collisions

Assessment

• Airway
  • Prepare for potentially difficult airway
    • Increased soft tissue edema, breast enlargement, weight gain
  • Pregnant women at increased risk of aspiration due to delayed gastric emptying
  • Failed intubations 8 times more likely in pregnant trauma patients

• Breathing
  • Increased basal O2 requirement
  • Fetus is highly sensitive to maternal hypoxia
    • Keep maternal SpO2 >95%
  • Some recommend placement of thoracostomy tube 1-2 intercostal spaces higher than usual, when indicated

• Circulation
  • Fluid and blood product resuscitation should proceed according to ATLS
  • Placenta is highly responsive to vasopressors and can result in decreased placental perfusion
  • Compression of IVC by gravid uterus can decreased CO by 30%
    • If must be kept supine, allow patient to lay in left lateral position
    • May also manually displace uterus to the left if patient must be kept on backboard
  • Fetal risks from defibrillation of mother are small

Complications

• Uterine rupture
  • More common with direct abdominal trauma in second half of pregnancy
  • Occurs in severe MVAs resulting in pelvic fractures, penetrating trauma
  • Signs and Sx
    • maternal shock
    • abdominal distension
    • abnormal uterine contour
    • abnormal fetal lie (oblique or transverse)
    • palpable fetal parts
    • sudden abnormal FHR pattern
    • ascent of fetal presenting part

• Placental Abruption
  • Most common cause of fetal demise in blunt trauma
  • US alone not sensitive → do not delay treatment for ultrasound if abruption suspected
  • Signs and Sx
    • abdominal pain
    • uterine tenderness
    • vaginal bleeding (70%, may be absent if retroplacental)
    • uterine contractions or hypertonicity
    • signs of fetal distress on toco monitor are often the earliest indicator
      • decelerations, tachycardia, bradycardia, and loss of variability

• Preterm labor
  • Trauma in pregnancy is associated with 2x higher risk of preterm delivery

Differential Diagnosis

Abdominal Trauma

• Abdominal compartment syndrome
• Diaphragmatic trauma
• Duodenal hematoma
• Genitourinary trauma
• Liver trauma
• Pelvic fractures
  • Acetabular pelvic fractures
  • Open book pelvic fracture
  • Straddle pelvic fracture
  • Pelvic avulsion fracture
• Retroperitoneal hemorrhage
• Renal trauma
• Splenic trauma
• Trauma in pregnancy
• Ureter trauma

Evaluation

• Trauma labs
• Rh factor
• Coag studies
• D-dimer
• Fibrinogen
• FAST - sensitivity similar to non-pregnant trauma population
• Radiographic imaging as directed by ATLS assesment
  • Radiographic imaging should not be delayed or deferred due to concern for fetal radiation exposure in the trauma setting
• Tocographic and fetal monitoring - VEAL CHOP
  • Variable - Cord compression
  • Early - Head compression
  • Accelerations - Okay
  • Late - Placental insufficiency

Treatment & Disposition

Assessment and stabilization of the mother should take first priority

• Nonviable fetus (<23-24wks)
  • Standard treatment for trauma
    • No obstetric intervention will alter the outcome of a pre-viable fetus
  • Consider RhoGAM 50mcg in Rh negative patients
• Viable fetus (>23-24wks)
  • Consider RhoGAM 300mcg in Rh negative patients
  • Avoid pressors - compromises blood flow to uterus leading to decreased fetal O2 delivery
  • Fetal monitoring (continuous cardiotocographic monitoring)
    • If no risk factors for fetal loss, minimum 4-6 hours
    • If risk factors for fetal loss/abruption, monitor for 24 hours
      • The duration of cardiotocographic monitoring should be extended to 24 hours if, during the first 4 hours, she develops > 4 contractions per hour, persistent uterine tenderness, a worrisome fetal monitor strip, vaginal bleeding, or rupture of the membranes.

• Allow patient to roll onto left side to unload uterine compression of IVC → increases venous return to heart
• In the setting of maternal cardiac arrest, consider Perimortem Cesarean delivery if no ROSC within 4 minutes

Abnormal Monitoring

• >3 contractions/hr
• Persistent uterine TTP
• Worrisome strip
• Vaginal bleeding
• PROM
• Serious maternal injury

Partial abruption with stable mom/fetus and <32wk may have expectant care (with easy access to emergent C-section)

Abruption = risk DIC

• Frequent uterine activity more predictive of abruption than US
  • >8 contractions/hr for 4hrs - high risk for abruption
  • 3-7 contractions/hr for 4hrs - extend monitoring for 24hrs
  • <3 contractions/hr for 4hrs - safe for discharge

External Links

• MDCalc - Pregnancy Due Dates Calculation

See Also

• Fetal Maternal Hemorrhage (RhoGAM)
• Perimortum C-Section
• Abruption
• Maternal Vitals and Labs in Pregnancy
• Trauma (main)
• Pregnancy (main)