Trauma Evaluation in Late Pregnancy (Knee Fall at 31 Weeks)
Pregnancy at 31 weeks warrants immediate assessment for maternal injury and obstetric complications after a fall. Maternal stabilization should be prioritized, with fetal monitoring added for pregnancies beyond viability when indicated by mechanism, symptoms, or concerning findings [1], [2].
Immediate Maternal Assessment Priorities
Primary survey should follow standard trauma principles (airway, breathing, circulation). Pregnant status should be recognized during the initial evaluation for altered physiology and altered priorities in imaging and fetal monitoring [2], ATLS pregnancy trauma toolkit excerpts.
Focused Obstetric Evaluation After Trauma
Obstetric assessment should include gestational age confirmation, evaluation for uterine tenderness, vaginal bleeding, leaking of fluid, uterine contractions, and assessment of fetal movements. Placental abruption, preterm labor, and preterm rupture of membranes are key late-pregnancy complications to evaluate after trauma [2], [3].
Fetal Monitoring Duration and Triggers
Electronic fetal heart rate and uterine monitoring (cardiotocography with tocodynamometry) is recommended for pregnancies >24 weeks after maternal trauma, typically for 4–6 hours for minor trauma presentations without ongoing concerning features. Continuous monitoring should be continued longer when abnormal fetal testing, uterine activity, bleeding, or uterine tenderness is present [2], [3], ATLS pregnancy trauma toolkit excerpt.
Rh Status and Prevention of Alloimmunization
Maternal Rh status should be determined during trauma evaluation. Rh-negative patients should receive Rh immune globulin after trauma per trauma-based pregnancy protocols ATLS pregnancy trauma toolkit excerpt.
Musculoskeletal Knee Injury Workup in Pregnancy
Knee injury evaluation should focus on fracture/dislocation screening, neurovascular status, and soft-tissue injury assessment. Imaging should be performed when clinically indicated to rule out fracture or other urgent pathology, because medically necessary diagnostic imaging should not be withheld solely due to pregnancy [4].
Imaging Selection and Safety Principles
Ultrasonography and MRI are preferred when they address the clinical question. Diagnostic radiography and CT should be used when medically necessary, with radiation exposure kept as low as reasonably achievable, since diagnostic imaging doses are generally much lower than thresholds associated with fetal harm [4], [5].
Indications for Escalation to Higher Level Obstetric Care
Escalation is indicated for any of the following after a fall: vaginal bleeding, uterine contractions, uterine tenderness, suspected rupture of membranes, abnormal fetal heart rate testing, or concern for significant mechanism with occult injury. Multidisciplinary management with obstetrics and trauma services is recommended based on severity and gestational age [3], [1].