Radiation Exposure in Pregnancy

1. Adverse Effects: Plain XRay - Radiation Exposure to unshielded Uterus
   1. Abdominal XRay
      1. PA: 0.1 - 0.3 RADS
      2. AP: <0.9 RADS
   2. Lumbar Spine XRay: 0.35 to 0.62 RADS
   3. Pelvis XRAy (AP): 0.04 to 0.24 RADS
   4. Hip and femur: 0.051 to 0.37 RADS
   5. Minimal to no radition exposure (<0.01 RADS)
      1. Chest XRay
      2. Cervical Spine XRay
      3. Thoracic spin XRay (AP)
      4. Upper or lower extremity (not including hip)
2. Adverse Effects: CT - Radiation exposure to unshielded Uterus
   1. CT Upper Abdomen (10 slice) : 0.24 to 2.6 RADS
   2. CT Entire Abdomen: <4.6 RADS
   3. CT Head: <0.05 RADS
   4. CT Pelvis: 0.73 to 4.6 RADS
   5. CT Chest: 0.10 to 0.45 RADS
   6. CT Lumbar Spine: 3.5 RADS
3. Adverse Effects: Miscellaneous Contrast Studies
   1. Barium Enema: 0.7 to 4.0 RADS
   2. Intravenous Pyelogram (IVP): 0.36 to 1.40 RADS
   3. Ventilation-Perfusion Scan: 0.06 to 1.0 RADS
   4. Upper GI Series: 0.048 to 0.36 RADS
4. Adverse Effects: Harmful Radiation Levels to fetus
   1. RADS: 0
      1. Childhood cancer risk 0.3% (background, baseline risk without radiation esposure)
   2. RADS: 0-5
      1. Childhood cancer risk 0.3 to 1%
   3. RADs: 5-50
      1. Fetal Exposure in first 47 days
         1. Spontaneous Abortion (especially in first 2 weeks)
         2. Associated with major malformations or IUGR in surviving fetus
      2. Fetal Exposure from 8-15 weeks (During fetogenesis)
         1. Live fetus
         2. Risk of congenital malformation increased 1 to 3%
         3. Mental retardation and other CNS effects
         4. Microcephaly
         5. Intrauterine Growth restriction
         6. Childhood cancer risk 1-6%
   4. RADs: >50
      1. Childhood cancer risk >6%
      2. High risk of abortion, major malformations, reduced IQ
5. Prevention: Reduction of fetal exposure
   1. Avoid radiation exposure in first trimester
   2. Consider cone to focus radiation beam
      1. Focus on suspected area of concern
   3. Shield gravid Pelvis
   4. Avoid dental radiography during pregnancy
      1. Associated with low birth weight infants
      2. Likely mediated via Thyroid exposure
      3. Hujoel (2004) JAMA 291:1987-93
6. References
   1. North (2002) J Am Coll Surg 194:100-1
   2. De Santis (2007) Birth Defects Res C Embryo Today 81(3): 177-82
   3. Doll (1997) Br J Radiol 70:130-9
   4. Streffer (2003) Ann ICRP 33(1-2):5-206
   5. Williams (2010) Am Fam Physician 82(5): 488-93