Trauma remains the leading cause of morbidity and mortality in pregnant women. It increases the risk of preterm delivery, placenta abruption, fetomaternal hemorrhage, and pregnancy loss. Motor Vehicle Accidents (MVAs) account for 70% of blunt abdominal trauma, then comes falls and direct assaults.
Evaluating and managing pregnant trauma patients requires knowing some physiological changes in pregnancy.
Physiological changes in pregnancy
Important actions in pregnant trauma patients
Rhogam (Rh immunoglobulin) and Tetanus Prophylaxis
Administer RhoD (Human Rho(D) immune globulin) to Rh-negative women; 50 mcg for <12 weeks, 300 mcg for >12 weeks. Tetanus prophylaxis is safe but considered as category C.
Images and Radiation Exposure
Do not withhold needed images. The greatest risk to fetal viability from ionizing radiation is within the first 2 weeks after conception and the highest malformation during the embryogenic organogenesis at 2-8 weeks. The risk of central nervous system teratogenesis is highest at 8-16 weeks. A dose of 5 rad is the threshold for human teratogenesis. Plain radiographs is <1 rad. Abdominal CT + Pelvic angio has the highest dose of rad (2.5-3.5). One of the critical problems is the abruption of the placenta, and CT is sensitive for abruption placenta, 86%, and has 98% specificity. The iodine contrast could cross the placenta and causing neonatal hypothyroidism.
Pelvic exam can be done only after performing an ultrasound to determine the placenta location and exclude placenta previa.
Vaginal fluid pH. If the pH is 7, it is amniotic fluid. If the pH is 5, it is vaginal secretions. Ferning on microscope slide = amniotic fluid.
APT ( alkali denaturation) test is qualitative evaluation to determine the presence of fetal Hg in maternal blood.
Kleihauer-Betke test measures fetal hemoglobin transfer to mothers’ blood.
The fetus will likely be viable at 24 weeks and above.
The normal fetal heart rate is 120-160 bpm. Heart rate below and above these limits is critical. Because ultrasound may not detect placenta abruption, nor rupture or fetal-placental injuries, high-suspicion and close monitorization are necessary.
4-6 hours will be enough for most of the cases. Persistent contractions or uterine irritability needs an external CTG for 24 hrs. Fewer than 3 contractions per hour could indicate a safe discharge.
Indication for Emergency C-Section
- Fetal tachycardia.
- Lack of beat to beat on long term viability.
- Late deceleration = fetal distress.
C-section has a 75% survival rate in 26 weeks or above. If the fetal heartbeats are present and the procedure was performed early, the success rate is higher.
References and Further Reading
- Tintinalli, J., Stapczynski, J., Ma, O. J., Cline, D., Cydulka, R., & Meckler, G. (2010). Tintinalli’s emergency medicine: a comprehensive study guide: a comprehensive study guide. McGraw Hill Professional.