Is an X-ray (X-radiation) safe for pregnant patients?

X-ray Safety During Pregnancy

X-rays should generally be avoided during pregnancy unless medically necessary, as they expose the fetus to ionizing radiation, though most diagnostic X-rays deliver doses well below the threshold for fetal harm. 1

Radiation Risk Assessment

• Fetal doses below 50 mGy are not associated with detectable increases in adverse fetal outcomes 1
• Most diagnostic X-ray studies deliver far less than 20 mGy to the uterus, including single-phase CT studies of the abdomen 1
• The threshold for significant risk of fetal damage is set at 100 mGy 1
• Simple X-rays with proper abdominal shielding carry negligible fetal radiation exposure of <0.1 mGy 1

Safety Considerations by Body Region

• Chest radiography during first and second trimesters, and extremity or head/neck radiography, may be performed safely with minimal fetal risk 1
• Abdominal/pelvic imaging with X-rays should be avoided when possible due to direct fetal exposure 1
• CT imaging of the abdomen and pelvis is not supported as initial imaging in pregnant patients due to ionizing radiation risk to the embryo/fetus 1

Alternative Imaging Modalities

• Ultrasound and MRI are preferred imaging modalities during pregnancy as they do not use ionizing radiation 1
• MRI is generally safe in pregnancy and can be useful for detecting various conditions without exposing the fetus to radiation 1
• MRI without contrast is preferred; gadolinium-based contrast agents should be avoided during pregnancy unless absolutely necessary 1

Risk-Benefit Assessment

• The medical necessity of the examination must outweigh potential risks to the fetus 1, 2
• When a diagnostic X-ray is medically indicated, the risk to the mother of not performing the procedure is usually greater than the potential harm to the fetus 3
• For urgent or emergent conditions where alternative imaging is inadequate, X-ray imaging may be necessary despite pregnancy 2

Practical Recommendations

• All women of childbearing age (typically 12-50 years) should be questioned about pregnancy status before imaging 1
• For high-dose procedures like fluoroscopy, pregnancy testing within 72 hours is recommended unless medical urgency prevents it 1
• Proper shielding of the abdomen should be used whenever possible to minimize fetal exposure 1
• The ALARA principle (As Low As Reasonably Achievable) should be followed to minimize radiation exposure 1

Common Pitfalls and Caveats

• Unnecessary termination of pregnancies due to fear of radiation effects often occurs due to lack of knowledge 3
• The risk of childhood malignancy from in utero radiation exposure is very small (estimated at one additional cancer death per 1700 exposures at 10 mGy) 4
• Special consideration is needed for nuclear medicine procedures, particularly those using radioactive iodine, which can cross the placenta and affect the fetal thyroid after 12 weeks gestation 1, 5
• Diagnostic X-rays pose no risk to lactation, and lactating women do not need to discontinue breastfeeding after receiving intravenous iodinated contrast 1

In summary, while X-rays should be avoided during pregnancy when possible, most diagnostic X-rays deliver radiation doses well below the threshold for fetal harm. When medically necessary, the benefits of diagnostic X-rays typically outweigh the minimal risks to the fetus, especially when proper shielding is used and exposure is limited to areas away from the abdomen and pelvis.