Snapshot A 25-year-old G1P0 woman at 36 weeks of gestation presents to the emergency department after a motor vehicle crash. She was wearing her seatbelt when another vehicle crashed into her car's rear-end. The airbag did not deploy, but the patient denies any pain or discomfort. Her blood pressure is 110/80 mmHg, pulse is 115/min, respirations are 24/min, and SaO2 is 96% on RA. Fetal monitoring reveals contractions every 10 minutes the pulse is 165/min. One hour later, the nurse notices that the patient's bedsheet is soaked with blood. Transabdominal and transvaginal ultrasound reveal placenta previa. One liter of normal saline is infused through a large-bore IV, a type and cross sample is obtained, and RhoGAM is prepared as the patient is rushed to the OR for emergent delivery. Introduction Overview trauma during pregnancy is the leading non-obstetric cause of mortality among pregnant women most common causes motor vehicle crash intimate partner violence assaults falls Epidemiology Incidence 1 in 12 pregnant women Risk factors incorrect seat belt use intimate partner violence ETIOLOGY Pathophysiology traumatic injuries are either unintentional or intentional and classified as either minor or major trauma minor trauma does not involve the abdomen and the patient does not report pain, vaginal bleeding, loss of fluid, or decreased fetal movement 90% of traumatic injuries during pregnancy are minor injuries pregnancy alters maternal physiology and anatomy near term, IVC compression in supine position can decrease cardiac output by 30-40% systolic blood pressure drops 5-15 mmHg in 2nd trimester, increases to normal by term maternal pulse increases 15-20/min by 3rd trimester physiologic macrocytic anemia is present (Hb 10-12 g/dL) leukocyte count increases to high of 20,000/uL blood volume increases in pregnancy up to 50% pregnant woman may lose 35% blood volume without typical signs of shock Presentation Symptoms variable depending on the type of injury Physical exam variable depending on the type of injury fetal heart rate changes may suggest a decrease in uteroplacental circulation from blood loss Imaging Ultrasound indications assess for placental abruption Studies Kleihauer-Betke test indications identification of fetal blood cells to screen for the degree of fetomaternal hemorrhage measures the amount of fetal hemoglobin transferred from a fetus to a mother's bloodstream can inform Rh Ig therapy in Rh-negative patients to prevent Rh disease in future pregnancies Treatment Medical primary survey with resuscitation focus of primary survey is on mother not fetus every female of reproductive age with significant injuries should be considered pregnant in the emergency setting until proven otherwise airway if Glasgow Coma Scale score < 10, consider nasogastric tube to prevent aspiration of acidic gastric content breathing if thoracostomy necessary, tube should be inserted 1 or 2 intercostal spaces higher than usual circulation use left lateral decubitus positioning or hip bolster to alleviate compression of inferior vena cava and increase blood return if blood pressure is low obtain PT/INR, PTT, D-dimer, and fibrinogen consider RhoGAM and O-negative blood until crossmatched blood becomes available if patient enters cardiac arrest, cesarean section should be performed for viable pregnancies (> 23 weeks) as soon as possible to facilitate maternal resuscitation and fetal salvage fetal evaluation obtain obstetric consultation if fetus is > 23 weeks and mother is stabilized, start fetal monitoring evaluate for uterine contractions, placental abruption, or traumatic uterine rupture if vaginal bleeding is present, do NOT perform speculum or digital vaginal exam obtain ultrasound to evaluate for placenta previa secondary survey obtain thorough medication and substance use history, as well as obstetric history radiographic studies needed for maternal evaluation including CT scan should NOT be deferred or delayed due to fetal exposure concerns for penetrating trauma, tetanus vaccination is safe in pregnancy every female trauma patient should be questioned specifically for intimate partner violence asking about abuse is the strongest predictor of disclosure HITS screening tool: How often does your partner... physically Hurt you? Insult you? Threaten you with harm? Scream or curse at you? involve a social worker reassure that the patient is not to blame and that assault is a crime document all evidence of abuse for medicolegal purposes Complications Placental abruption may occur when acceleration-deceleration forces shear the placenta from its implantation site most common cause of fetal death when the mother survives the trauma incidence 35-65% of major injuries 2-4% of minor injuries Exsanguination rupture of the uterus or severe damage to the uterine vessels may cause rapid exsanguination due to significant increases in uterine blood flow uterine rupture complications 0.6% of traumatic injuries in pregnancy Retroperitoneal hemorrhage may be a sequela of pelvic fracture Rupture of amniotic membranes may lead to chorioamnionitis, preterm labor, and umbilical cord prolapse Prognosis 60-70% of fetal losses after trauma are a result of minor traumatic injuries