Obstetrics Book

http://www.fpnotebook.com/

Radiation Exposure in PregnancyAka: Fetal Radiation Exposure

Advertisement

  1. Radiation Exposure to unshielded uterus: Plain XRay
    1. Abdominal XRay
      1. PA: <0.3 RADS
      2. AP: <0.9 RADS
    2. Lumbar Spine XRay: 0.031 to 4.0 RADS
    3. Pelvis XRAy (AP) <2.2 (usually 0.2)
    4. Minimal to no radition exposure
      1. Chest XRay
      2. Cervical Spine XRay
      3. Thoracic spin XRay (AP)
      4. Femur XRay
    5. Intravenous Pyelogram (IVP) RADS: 0.4 to 1.2
  2. Radiation exposure to unshielded uterus: CT
    1. CT Upper Abdomen: <3.5 RADS
    2. CT Entire Abdomen: <4.6 RADS
    3. CT Head: <0.05 RADS
    4. CT Pelvis: <5 RADS
    5. CT Chest: <0.60 RADS
  3. Harmful Radiation Levels to fetus
    1. RADs: 5-10
      1. Fetal Exposure in first 47 days: Spontaneous Abortion
      2. Fetal Exposure after 47 days: Live fetus
        1. Risk of congenital malformation increased 1 to 3%
        2. Mental retardation and other CNS effects
        3. Microcephaly
        4. Intrauterine Growth restriction
      3. First trimester exposure (especially <8 weeks)
        1. Risk of childhood cancer
        2. Doll (1997) Br J Radiol 70:130
    2. RADs: 200
      1. Infertility Risk
      2. Higher risk to fetus in early pregnancy
  4. 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
  5. References
    1. North (2002) J Am Coll Surg 194:100

Navigation Tree