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Emergency And Acute Medicine – Pregnancy, Trauma In
Trauma complicates approximately 7% of all pregnancies and is the most common cause of nonobstetric maternal morbidity and mortality. Fetal loss ranges from 3.4–38% depending on injury severity. After the first trimester, trauma increases fetal loss but does not significantly increase maternal mortality. The likelihood of fetal injury rises with the severity of maternal insult. Physiologic hypervolemia in pregnancy may mask blood loss, and clinical shock may not be apparent until 30% of maternal blood volume is lost. Abdominal findings are often subtle in gravid patients. Even minor trauma accounts for at least 50% of fetal losses, and an Injury Severity Score greater than 9 is associated with worse outcomes. Pelvic fractures carry increased maternal and fetal morbidity due to engorged pelvic organs and vasculature.
Fetal and uterine complications include placental abruption, fetomaternal hemorrhage (FMH), premature labor, uterine contusion or rupture, premature rupture of membranes, fetal hypoxia, direct fetal injury, and fetal demise. Placental abruption occurs in up to 60% of severe trauma and 1–5% of minor injuries, accounting for up to 50% of fetal losses. It may occur without external bleeding in 20% of cases and is characterized by uterine contractions, abdominal pain, and vaginal bleeding. Uterine rupture, more common in patients with prior cesarean section, carries nearly universal fetal mortality and approximately 10% maternal mortality. FMH occurs in more than 30% of severe trauma and can cause isoimmunization in Rh-negative mothers with as little as 0.03 mL of fetal blood. Falls, which affect one in four pregnant women, significantly increase risks of preterm birth, abruption, fetal distress, and fetal hypoxia. Burns involving more than 40% total body surface area approach 100% maternal and fetal mortality. Domestic violence, electrocution, penetrating trauma, and motor vehicle accidents are major contributors.
Motor vehicle accidents account for 48–84% of traumatic events in pregnancy, followed by domestic violence, falls, direct abdominal trauma, penetrating injuries, burns, and electrical injuries. Trauma occurs more frequently in younger women and is often associated with substance abuse or suicidal behavior.
Evaluation begins with a focused history including mechanism of injury, gestational age, last menstrual period, abdominal pain, uterine contractions, vaginal bleeding, leakage of fluid, prior cesarean sections, and substance use. Examination should follow primary, secondary, and tertiary trauma surveys with the patient positioned in the left lateral recumbent position when feasible. Findings suggestive of placental abruption include uterine tenderness and contractions. Uterine rupture may present with abnormal uterine contour and palpable fetal parts. Gestational age estimation is critical for assessing viability; after 16 weeks, fundal height in centimeters approximates gestational age in weeks.
Initial management prioritizes maternal stabilization with airway management and resuscitation as indicated. Spinal immobilization should be maintained. Oxygen, cardiac monitoring, pulse oximetry, and intravenous access are essential. The patient or backboard should be tilted 15–30 degrees to the left to prevent supine hypotension. Lactated Ringer solution is preferred; blood loss should be replaced in a 3:1 crystalloid-to-blood ratio. If severe hemorrhage occurs, balanced transfusion with packed red blood cells, plasma, and platelets in a 1:1:1 ratio reduces coagulopathy. O-negative blood should be used if type-specific blood is unavailable. Nasogastric decompression reduces aspiration risk, and Foley catheterization monitors urine output. Rapid sequence intubation is safe and preferred when needed.
Fetal assessment includes Doppler fetal heart tones and continuous fetal monitoring for viable fetuses, generally beyond 24 weeks’ gestation. Monitoring should continue for at least 4–6 hours. Absence of contractions during the first 4 hours makes abruption unlikely. More than eight contractions per hour or persistent contractions increase the risk of adverse outcomes. Fetal bradycardia, poor variability, or late decelerations indicate distress. A normal tracing with normal maternal examination has a near 100% negative predictive value for adverse outcomes.
Laboratory evaluation includes complete blood count, blood gas and electrolytes, urinalysis, blood type and Rh status, and Kleihauer–Betke testing to quantify FMH. Rh-negative patients should receive Rho(D) immune globulin within 72 hours: 50 μg before 12 weeks and 300 μg after 12 weeks, with repeat dosing if significant FMH is detected. Imaging studies necessary for maternal evaluation should not be withheld; shielding is recommended when possible. Radiation doses under 1 rad (10 mGy) carry minimal risk, while malformation risk increases at 5–10 rad. FAST ultrasound evaluates hemoperitoneum, fetal viability, gestational age, and amniotic fluid but may miss placental abruption.
Tocolytic therapy may be considered in hemodynamically stable patients with persistent contractions lasting more than 4 hours, typically using magnesium sulfate 4 g IV. Tocolytics are contraindicated with cervical dilation greater than 4 cm or when abruption or FMH is suspected. Perimortem cesarean delivery should be considered within 4–5 minutes of maternal cardiac arrest in viable pregnancies. In minor trauma beyond 20 weeks, monitoring is best conducted in a labor and delivery setting.
Admission is required for vaginal bleeding, amniotic fluid leakage, abdominal pain, uterine contractions, FMH, fetal distress, placental abruption, or evidence of internal injury. Discharge may be considered only after at least 4 hours of monitoring without contractions, bleeding, tenderness, or fetal distress, and only in consultation with obstetrics. Clear return precautions and prompt obstetric follow-up are mandatory.
Minor trauma can result in significant maternal or fetal morbidity and mortality. Stabilization of the mother is always the first priority, as maternal resuscitation optimizes fetal outcome. Clinicians must remember that signs of maternal shock may not appear until 1,500–2,000 mL of blood loss has occurred.
Trauma complicates approximately 7% of all pregnancies and is the most common cause of nonobstetric maternal morbidity and mortality. Fetal loss ranges from 3.4–38% depending on injury severity. After the first trimester, trauma increases fetal loss but does not significantly increase maternal mortality. The likelihood of fetal injury rises with the severity of maternal insult. Physiologic hypervolemia in pregnancy may mask blood loss, and clinical shock may not be apparent until 30% of maternal blood volume is lost. Abdominal findings are often subtle in gravid patients. Even minor trauma accounts for at least 50% of fetal losses, and an Injury Severity Score greater than 9 is associated with worse outcomes. Pelvic fractures carry increased maternal and fetal morbidity due to engorged pelvic organs and vasculature.
Fetal and uterine complications include placental abruption, fetomaternal hemorrhage (FMH), premature labor, uterine contusion or rupture, premature rupture of membranes, fetal hypoxia, direct fetal injury, and fetal demise. Placental abruption occurs in up to 60% of severe trauma and 1–5% of minor injuries, accounting for up to 50% of fetal losses. It may occur without external bleeding in 20% of cases and is characterized by uterine contractions, abdominal pain, and vaginal bleeding. Uterine rupture, more common in patients with prior cesarean section, carries nearly universal fetal mortality and approximately 10% maternal mortality. FMH occurs in more than 30% of severe trauma and can cause isoimmunization in Rh-negative mothers with as little as 0.03 mL of fetal blood. Falls, which affect one in four pregnant women, significantly increase risks of preterm birth, abruption, fetal distress, and fetal hypoxia. Burns involving more than 40% total body surface area approach 100% maternal and fetal mortality. Domestic violence, electrocution, penetrating trauma, and motor vehicle accidents are major contributors.
Motor vehicle accidents account for 48–84% of traumatic events in pregnancy, followed by domestic violence, falls, direct abdominal trauma, penetrating injuries, burns, and electrical injuries. Trauma occurs more frequently in younger women and is often associated with substance abuse or suicidal behavior.
Evaluation begins with a focused history including mechanism of injury, gestational age, last menstrual period, abdominal pain, uterine contractions, vaginal bleeding, leakage of fluid, prior cesarean sections, and substance use. Examination should follow primary, secondary, and tertiary trauma surveys with the patient positioned in the left lateral recumbent position when feasible. Findings suggestive of placental abruption include uterine tenderness and contractions. Uterine rupture may present with abnormal uterine contour and palpable fetal parts. Gestational age estimation is critical for assessing viability; after 16 weeks, fundal height in centimeters approximates gestational age in weeks.
Initial management prioritizes maternal stabilization with airway management and resuscitation as indicated. Spinal immobilization should be maintained. Oxygen, cardiac monitoring, pulse oximetry, and intravenous access are essential. The patient or backboard should be tilted 15–30 degrees to the left to prevent supine hypotension. Lactated Ringer solution is preferred; blood loss should be replaced in a 3:1 crystalloid-to-blood ratio. If severe hemorrhage occurs, balanced transfusion with packed red blood cells, plasma, and platelets in a 1:1:1 ratio reduces coagulopathy. O-negative blood should be used if type-specific blood is unavailable. Nasogastric decompression reduces aspiration risk, and Foley catheterization monitors urine output. Rapid sequence intubation is safe and preferred when needed.
Fetal assessment includes Doppler fetal heart tones and continuous fetal monitoring for viable fetuses, generally beyond 24 weeks’ gestation. Monitoring should continue for at least 4–6 hours. Absence of contractions during the first 4 hours makes abruption unlikely. More than eight contractions per hour or persistent contractions increase the risk of adverse outcomes. Fetal bradycardia, poor variability, or late decelerations indicate distress. A normal tracing with normal maternal examination has a near 100% negative predictive value for adverse outcomes.
Laboratory evaluation includes complete blood count, blood gas and electrolytes, urinalysis, blood type and Rh status, and Kleihauer–Betke testing to quantify FMH. Rh-negative patients should receive Rho(D) immune globulin within 72 hours: 50 μg before 12 weeks and 300 μg after 12 weeks, with repeat dosing if significant FMH is detected. Imaging studies necessary for maternal evaluation should not be withheld; shielding is recommended when possible. Radiation doses under 1 rad (10 mGy) carry minimal risk, while malformation risk increases at 5–10 rad. FAST ultrasound evaluates hemoperitoneum, fetal viability, gestational age, and amniotic fluid but may miss placental abruption.
Tocolytic therapy may be considered in hemodynamically stable patients with persistent contractions lasting more than 4 hours, typically using magnesium sulfate 4 g IV. Tocolytics are contraindicated with cervical dilation greater than 4 cm or when abruption or FMH is suspected. Perimortem cesarean delivery should be considered within 4–5 minutes of maternal cardiac arrest in viable pregnancies. In minor trauma beyond 20 weeks, monitoring is best conducted in a labor and delivery setting.
Admission is required for vaginal bleeding, amniotic fluid leakage, abdominal pain, uterine contractions, FMH, fetal distress, placental abruption, or evidence of internal injury. Discharge may be considered only after at least 4 hours of monitoring without contractions, bleeding, tenderness, or fetal distress, and only in consultation with obstetrics. Clear return precautions and prompt obstetric follow-up are mandatory.
Minor trauma can result in significant maternal or fetal morbidity and mortality. Stabilization of the mother is always the first priority, as maternal resuscitation optimizes fetal outcome. Clinicians must remember that signs of maternal shock may not appear until 1,500–2,000 mL of blood loss has occurred.
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