Trauma in Pregnancy Assessment

Trauma in pregnancy is the leading non-obstetric cause of maternal death, complicating approximately 1 in 12 pregnancies and responsible for 7% of all maternal deaths. The management of the pregnant trauma patient requires simultaneous care of two patients — mother and fetus — with specific anatomical, physiological, and resuscitative considerations that differ substantially from non-pregnant trauma care. Gestational age is the fundamental determinant of uterine position and thus injury risk: at 12 weeks the uterus is palpable at the pubic symphysis and is protected by the bony pelvis; at 20 weeks it reaches the umbilicus; at 36 weeks it is at the xiphoid process. Beyond 20 weeks, the enlarged uterus compresses the inferior vena cava when the patient lies supine (aortocaval compression), reducing venous return and cardiac output by up to 30% — left lateral tilt of 15–30 degrees is mandatory in all pregnant patients beyond 20 weeks unless spinal injury is suspected, in which case manual uterine displacement is used. Fetal monitoring should be initiated as soon as the patient is stabilised for any viable fetus (typically ≥24 weeks gestational age) and continued for a minimum of 4–6 hours after minor trauma and 24 hours if any uterine contractions, haemorrhage, or abnormal fetal heart rate patterns are detected. Placental abruption — traumatic separation of the placenta from the uterine wall — is the most common cause of fetal death from maternal trauma, preceding maternal haemodynamic instability. All Rh-negative pregnant trauma patients must receive anti-D immunoglobulin (RhIG) after any abdominal trauma, and the dose should be guided by a Kleihauer-Betke test measuring fetal red blood cells in maternal circulation.

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1. 1Establish gestational age and fetal viability immediately upon patient arrival: confirm dates from patient history, last menstrual period, or prior obstetric records; perform point-of-care ultrasound (FAST exam) to assess fundal height and fetal heart activity; identify gestational age ≥24 weeks as the threshold for fetal monitoring.
2. 2Position immediately: apply left lateral tilt of 15–30 degrees (wedge under right hip) or use manual left uterine displacement if spinal trauma is suspected — this relieves aortocaval compression, restoring venous return and preventing maternal hypotension-induced fetal hypoperfusion.
3. 3Apply standard ATLS primary survey (ABCDE) with pregnancy-specific modifications: anticipate difficult airway (laryngeal oedema, large breasts); position head up 30 degrees if possible; use RSI for intubation with cricoid pressure (modified for pregnancy); anticipate accelerated desaturation (reduced FRC + increased O₂ consumption).
4. 4Recognise physiological differences: normal BP in pregnancy may be 10–15 mmHg lower than pre-pregnancy baseline; normal heart rate is 10–15 bpm higher; haemoglobin is diluted to 10–12 g/dL (physiological anaemia); plasma volume increases 40–50% — maternal vital signs may appear relatively normal despite significant blood loss before fetal compromise is apparent.
5. 5Initiate electronic fetal monitoring (cardiotocography, CTG) for all viable gestations (≥24 weeks): assess fetal heart rate baseline, variability, accelerations, and decelerations; uterine contractions at ≥4 per hour may indicate abruption or preterm labour; CTG should continue for minimum 4 hours after minor trauma, extended to 24 hours if any abnormality is detected.
6. 6Perform Kleihauer-Betke (KB) test in all Rh-negative pregnant trauma patients: KB identifies fetal erythrocytes in maternal circulation (fetomaternal haemorrhage); standard anti-D 300 mcg IM covers approximately 15 mL fetal red cells (or 30 mL fetal whole blood); larger fetomaternal haemorrhage requires additional anti-D doses calculated from KB result.
7. 7Consider delivery (emergency caesarean section) if: the fetus is viable (≥24 weeks) and there is evidence of non-reassuring fetal status on CTG despite resuscitation; placental abruption with maternal or fetal deterioration; uterine rupture suspected; or maternal cardiac arrest — perimortem caesarean section at 4 minutes of CPR may be life-saving for both.

• !Placing pregnant trauma patients supine for assessment and resuscitation beyond 20 weeks without applying left lateral tilt — aortocaval compression may account for haemodynamic instability before haemorrhage is identified.
• !Not initiating fetal monitoring for viable fetuses (≥24 weeks) in all trauma patients, even those without abdominal pain or visible injury — placental abruption may have no maternal symptoms initially.
• !Withholding CT imaging from pregnant trauma patients due to radiation concerns — the risk of undetected life-threatening injury to the mother vastly outweighs the minimal fetal radiation risk.
• !Failing to perform Kleihauer-Betke testing and administer anti-D to Rh-negative pregnant trauma patients — Rh sensitisation from even small fetomaternal haemorrhage can cause haemolytic disease in future pregnancies.
• !Inadequate fluid resuscitation — the physiological haemodilution of pregnancy and expanded plasma volume means standard vital sign thresholds may not trigger resuscitation early enough; have a low threshold for blood product administration.
• !Delaying perimortem caesarean section beyond 4–5 minutes of maternal cardiac arrest in a viable gestation — the window for both maternal and fetal survival narrows rapidly after 5 minutes.