Effective management of trauma in pregnancy requires a dual focus on two patients: the mother and the fetus. However, the sources emphasize that the best initial treatment for the fetus is the optimal resuscitation of the mother. To provide effective care, clinicians must navigate significant anatomical and physiological changes that alter injury patterns and responses to shock.

Physiological Adaptations and Hemodynamics Pregnancy induces hypervolemia, with plasma volume increasing steadily until 34 weeks. This allows a healthy pregnant patient to lose 1,200 to 1,500 mL of blood before exhibiting typical signs of hypovolemia, such as tachycardia or hypotension. Consequently, maternal vital signs may appear stable even when the fetus is in distress due to compromised uterine perfusion. The fetal heart rate is a sensitive indicator of maternal blood volume status and must be monitored; rates outside the normal 120–160 beats per minute range suggest decompensation.

A critical procedural adaptation involves patient positioning. In the supine position, the enlarged uterus compresses the inferior vena cava, potentially reducing cardiac output by 30%. To counteract this, patients requiring spinal motion restriction should be logrolled 15–30 degrees to the left to displace the uterus and maintain venous return.

Respiratory and Anatomical Changes Oxygen consumption increases during pregnancy, making the maintenance of adequate arterial oxygenation essential. Hormonal and mechanical changes lead to increased minute ventilation and a baseline state of hypocapnia (PaCO2 of 30 mm Hg). Therefore, a PaCO2 of 35 to 40 mm Hg, which is normal in nonpregnant patients, may indicate impending respiratory failure in a pregnant trauma patient. Anatomically, as the uterus rises out of the pelvis, it pushes the bowel upward. This affords the bowel some protection from blunt trauma but makes the uterus and placenta more vulnerable.

Specific Injuries and Management The leading cause of fetal death is maternal shock/death, followed by abruptio placentae (placental separation). Abruption may present with vaginal bleeding, uterine tenderness, and tetany, though vaginal bleeding is absent in 30% of cases. Uterine rupture is rare but catastrophic, marked by shock and palpable fetal parts outside the uterus.

Standard trauma diagnostics, including x-rays and CT scans, should not be withheld due to fetal radiation concerns if they are necessary for maternal evaluation. However, if diagnostic peritoneal lavage is used, the open technique above the umbilicus is required. All Rh-negative pregnant trauma patients should receive Rh immunoglobulin within 72 hours to prevent isoimmunization. In cases of maternal cardiac arrest, perimortem cesarean section may be attempted, with the best chance of success if performed within 4 to 5 minutes of arrest.

Intimate Partner Violence (IPV) Trauma frequently results from IPV, which affects 17% of injured pregnant patients. Clinicians must maintain a high index of suspicion, looking for indicators such as injuries inconsistent with the history, delayed care seeking, or a partner who dominates the interview. Screening questions regarding safety and fear should be asked when the partner is not present