What is the appropriate immediate management—including monitoring, obstetric ultrasound, trauma‑oriented imaging, and pregnancy‑compatible analgesia—for a 17‑year‑old gravida 1 para 0 female at 33 weeks gestation who was a restrained back‑seat passenger in a motor‑vehicle collision and now presents with an 8/10 throbbing headache, severe back pain worsened by movement, pinpoint right occipital neck pain, stable vital signs (tachycardia, mild tachypnea, normotension, normal temperature, SpO₂ 97 %), no loss of consciousness or neurologic deficits, and a history of chronic lower‑right back pain?

Immediate Management of Pregnant Trauma Patient at 33 Weeks Gestation

This 17-year-old at 33 weeks gestation requires immediate systematic obstetrical examination with continuous fetal heart rate monitoring for at least 4–6 hours, trauma-oriented imaging without delay (including CT if clinically indicated), manual left lateral uterine displacement during all assessments, and pregnancy-compatible analgesia—prioritizing maternal stabilization first while recognizing that even minor trauma significantly increases risks of placental abruption, preterm labor, and fetal death. 1

Immediate Obstetrical Assessment and Monitoring

All pregnant women beyond 20 weeks gestation who experience trauma require systematic obstetrical examination with fetal heart rate monitoring, as trauma significantly increases risks of preterm birth (OR 2.07), fetal distress (OR 1.84), and fetal death (OR 4.67) even after seemingly minor accidents. 2, 1

• Initiate continuous electronic fetal monitoring immediately for a minimum of 4–6 hours given she is at 33 weeks (≥23 weeks viable gestation). 1
• Extend monitoring to 24 hours because she has high-risk features: back pain worsening with movement (potential uterine irritability), headache following direct head impact, and motor vehicle collision mechanism. 2, 1
• Perform obstetrical ultrasound to assess fetal viability, amniotic fluid volume, placental location, and exclude placental abruption—the most common life-threatening obstetric complication following blunt trauma. 3, 4

Critical positioning consideration: Manually displace the gravid uterus to the left throughout all examinations and monitoring, as supine positioning at 33 weeks can reduce cardiac output by 30% due to aortocaval compression. 2, 1 Do not place her in left lateral decubitus position during initial trauma assessment, as this reduces the efficacy of resuscitation if needed; instead, assign a team member to provide continuous two-handed leftward uterine displacement. 2

Trauma-Oriented Imaging Without Delay

Perform all medically indicated radiographic studies, including CT scans, without delay or deferral due to fetal radiation concerns—the risk-benefit balance strongly favors maternal diagnosis and treatment. 1

Cervical Spine Imaging

Given her mechanism (head struck front seat then "snapped backwards" hitting back seat hard) with pinpoint right occipital neck pain and headache:

• Obtain CT cervical spine without contrast immediately as first-line imaging, which has 98–100% sensitivity for detecting cervical spine fractures. 5 She meets high-risk criteria: midline/occipital tenderness, high-energy mechanism (motor vehicle collision), and age <65 years with dangerous mechanism. 2, 5
• Plain radiographs are inadequate—they miss two-thirds of fractures visible on CT and have only 36% sensitivity for cervical injuries. 5

Thoracolumbar Spine Imaging

Given her severe back pain (9/10 with movement), middle and right-sided location, and motor vehicle collision:

• Obtain CT thoracolumbar spine without contrast because she meets multiple validated criteria for imaging: back/midline tenderness, motor vehicle collision mechanism, and pain worsening with movement suggesting potential instability. 2
• The seatbelt positioned "below her pregnancy belly" raises concern for thoracolumbar seatbelt injury—a mechanism associated with increased thoracolumbar fractures and, critically in pregnancy, uterine and placental injury. 2, 6

Head CT

Given her 8/10 throbbing headache, initial photophobia, and mechanism of direct head impact:

• Obtain CT head without contrast to exclude intracranial hemorrhage, especially given the biphasic mechanism (anterior impact then posterior "hard" impact). 1

Fetal radiation exposure from these CT studies is well below thresholds for adverse effects (<50 mGy), and delaying maternal diagnosis poses far greater risk to both mother and fetus. 1

Analgesia Management

Provide adequate analgesia prioritizing maternal comfort, as untreated pain increases catecholamine release that can compromise uteroplacental perfusion:

• Acetaminophen 1000 mg IV or PO as first-line for headache and moderate pain—safe throughout pregnancy. 2
• Opioids (morphine 2–4 mg IV or hydromorphone 0.5–1 mg IV) for severe pain (her 9/10 back pain with movement)—short-term use for acute trauma pain is appropriate and does not contraindicate breastfeeding. 2
• Avoid NSAIDs (including ketorolac) after 20 weeks gestation due to risk of premature ductus arteriosus closure and oligohydramnios.

Consider early neuraxial analgesia (epidural catheter placement) if she requires ongoing pain management and has no contraindications, as this provides superior analgesia and establishes access should emergent cesarean delivery become necessary. 2

Monitoring for Obstetric Complications

The most critical obstetric complications to monitor for are placental abruption, preterm labor, and uterine rupture—all can present with delayed onset after seemingly stable initial presentation. 3, 4

Signs requiring immediate obstetric intervention:

• Vaginal bleeding (any amount)
• Sustained uterine contractions (>1 per 10 minutes)
• Uterine tenderness or rigidity
• Non-reassuring fetal heart rate patterns
• Maternal hemodynamic instability
• Abdominal pain (new or worsening beyond her chronic back pain)

2, 1, 3

Seatbelt positioning "below her pregnancy belly and did not cross across her chest" is suboptimal and increases risk of direct uterine trauma—the lap belt should be positioned low across the pelvis/upper thighs, not across the gravid abdomen. 6 This mechanism warrants heightened surveillance for uterine and placental injury.

Laboratory Assessment

• Complete blood count to establish baseline hemoglobin and monitor for occult hemorrhage
• Type and screen given risk of placental abruption requiring transfusion
• Kleihauer-Betke test and RhoGAM administration (300 mcg IM) if she is Rh-negative, as even minor fetomaternal hemorrhage can cause alloimmunization
• Coagulation studies if any concern for placental abruption (which causes consumptive coagulopathy)

3, 4

Critical Pitfalls to Avoid

Do not delay imaging for "fetal safety"—maternal death or disability from missed injuries poses infinitely greater risk to the fetus than diagnostic radiation exposure. 1

Do not rely on maternal vital signs alone—pregnant women can lose 30–35% of blood volume before showing signs of shock due to physiologic hypervolemia of pregnancy. Her tachycardia (pulse 104) and tachypnea (RR 24) may represent early compensation. 4

Do not discharge after brief observation if monitoring shows any concerning features—fetal deaths have occurred 24–48 hours after trauma despite initially reassuring assessments. 2, 3

Do not attribute all back pain to her "chronic" pain—new or worsened pain after trauma requires structural evaluation for fracture, especially given the seatbelt mechanism. 2, 7

Do not forget that she is a minor (17 years old)—ensure appropriate consent processes and consider social work consultation given her young age and pregnancy status.