What is the management approach for a 33-week pregnant patient after a motor vehicle accident (MVA)?

Management of a 33-Week Pregnant Patient After Motor Vehicle Accident (MVA)

A 33-week pregnant patient who has experienced a motor vehicle accident requires immediate evaluation in a trauma unit or emergency room with subsequent fetal monitoring for at least 4 hours, regardless of the severity of maternal injuries.

Initial Assessment and Stabilization

• Every female of reproductive age with significant injuries should be considered pregnant until proven otherwise by a definitive pregnancy test or ultrasound scan 1
• Transfer to a trauma unit or emergency room is necessary for initial evaluation, regardless of gestational age, when the injury is major or severity is undetermined 1
• Assessment, stabilization, and care of the pregnant woman is the first priority; fetal heart rate monitoring should be initiated as soon as feasible if the fetus is viable (≥23 weeks) 1
• Oxygen supplementation should be given to maintain maternal oxygen saturation >95% to ensure adequate fetal oxygenation 1

Maternal Evaluation

• Two large-bore (14-16 gauge) intravenous lines should be placed in a seriously injured pregnant woman 1
• After mid-pregnancy, the gravid uterus should be moved off the inferior vena cava by manual displacement or left lateral tilt to increase venous return and cardiac output 1
• Radiographic studies indicated for maternal evaluation, including abdominal computed tomography, should not be deferred or delayed due to concerns regarding fetal exposure to radiation 1
• In addition to routine blood tests, a coagulation panel including fibrinogen should be obtained 1, 2
• Focused abdominal sonography for trauma (FAST) should be considered for detection of intraperitoneal bleeding 1

Fetal Assessment

• All pregnant trauma patients with a viable pregnancy (≥23 weeks) should undergo electronic fetal monitoring for at least 4 hours 1, 2
• An urgent obstetrical ultrasound scan should be undertaken when gestational age is undetermined and delivery is anticipated 1
• All pregnant trauma patients with a viable pregnancy who are admitted for fetal monitoring should have an obstetrical ultrasound prior to discharge from hospital 1

Extended Monitoring Criteria

• Pregnant trauma patients (≥23 weeks) should be admitted for observation for 24 hours if they have any of the following adverse factors 1:
  • Uterine tenderness
  • Significant abdominal pain
  • Vaginal bleeding
  • Sustained contractions (>1/10 min)
  • Rupture of membranes
  • Atypical or abnormal fetal heart rate pattern
  • High-risk mechanism of injury
  • Serum fibrinogen <200 mg/dL

Prevention of Rh Alloimmunization

• Anti-D immunoglobulin should be given to all rhesus D-negative pregnant trauma patients 1
• In Rh-negative pregnant trauma patients, quantification of maternal-fetal hemorrhage by tests such as Kleihauer-Betke should be done to determine the need for additional doses of anti-D immunoglobulin 1, 2

Monitoring for Placental Abruption

• Management of suspected placental abruption should not be delayed pending confirmation by ultrasonography, as ultrasound is not a sensitive tool for its diagnosis 1
• Placental abruption should be suspected with uterine tenderness, contractions, or abnormal fetal heart rate patterns 3
• When placental abruption is diagnosed during pregnancy, women should stop moderate to vigorous physical activity due to the high risks to both maternal and fetal health 3

Special Considerations for Fetal Growth Restriction (FGR)

• If the accident results in concerns about placental function and potential fetal growth restriction, follow-up ultrasound assessments should be scheduled 4
• For fetuses with FGR and normal Doppler, serial umbilical artery Doppler assessment is recommended every 2 weeks 4
• More frequent monitoring (weekly or 2-3 times per week) is required if abnormal Doppler findings develop 4

Common Pitfalls and Caveats

• Pregnant women admitted after MVA tend to sustain less severe injuries compared to non-pregnant women, but may require more genitourinary surgery (potentially indicating more cesarean deliveries) 5
• Vasopressors should be used only for intractable hypotension unresponsive to fluid resuscitation due to their adverse effect on uteroplacental perfusion 1
• The abdominal portion of military anti-shock trousers should not be inflated on a pregnant woman as this may reduce placental perfusion 1
• In cases of vaginal bleeding at or after 23 weeks, speculum or digital vaginal examination should be deferred until placenta previa is excluded by ultrasound 1