Are X-rays (x-radiation) safe during pregnancy?

X-ray Safety During Pregnancy

X-rays are generally safe during pregnancy when proper precautions are taken, as fetal radiation exposure from most diagnostic X-rays is well below the 50 mGy threshold where adverse fetal outcomes might be detected. 1, 2

Understanding Radiation Risk During Pregnancy

Radiation Dose Thresholds

• Fetal doses <50 mGy are not associated with detectable increases in adverse fetal outcomes 1
• Fetal doses between 50-500 mGy are associated with increased frequencies of adverse fetal effects 1
• Fetal doses >500 mGy are likely catastrophic but unlikely in medical radiation circumstances 1

Typical Fetal Radiation Exposure from Common X-rays

Procedure	Typical Fetal Dose
Chest X-ray	<0.01 mGy
Extremity or head/neck X-rays	Minimal exposure
CT chest	0.3 mGy
CT abdomen/pelvis	13-25 mGy

Safety of Specific X-ray Procedures During Pregnancy

Safe X-ray Procedures

• Chest radiography during first and second trimesters is considered safe and does not require pregnancy testing 1
• Extremity or head and neck radiography is not altered by pregnancy status and does not require pregnancy testing 1
• These procedures deliver far less than 20 mGy to the uterus 1

X-ray Procedures Requiring Caution

• Abdominal X-rays expose the fetus to direct radiation but still typically result in doses <10 mGy 3
• Fluoroscopic interventional procedures may deliver doses above 100 mGy and demand planning and caution 1
• For high-dose procedures, the American College of Radiology recommends a pregnancy test be obtained within 72 hours of the procedure, unless medical urgency prevents it 1

Best Practices for X-ray During Pregnancy

Radiation Protection Measures

• Use proper abdominal shielding when performing X-rays during pregnancy 2
• Follow the ALARA principle (As Low As Reasonably Achievable) 1, 2
• Optimize technique to minimize exposure while maintaining diagnostic quality 2

Alternative Imaging Modalities

• Ultrasound is the preferred first-line imaging modality during pregnancy 1, 2
• MRI without gadolinium can be safely used if ultrasound is inconclusive 1, 2
• CT scans, bone scans, and PET scans should be avoided throughout pregnancy unless absolutely necessary 1

Patient Counseling

Risk Communication

• Provide concrete information about radiation doses to alleviate anxiety 2
• Explain that the fetal dose from a chest X-ray is less than one day of natural background radiation 2
• Emphasize that diagnostic X-rays pose no risk to lactation 1

Special Considerations

• Nuclear imaging with radioactive iodine should be avoided as it can cross the placenta and affect the fetal thyroid gland 1, 3
• For nuclear cardiology perfusion imaging, if needed, Rb82 PET would cause the least fetal exposure 1

Clinical Decision-Making Algorithm

1. Determine necessity: Is the X-ray medically necessary? Can diagnosis be made without imaging?
2. Consider alternatives: Can ultrasound or unenhanced MRI provide adequate diagnostic information?
3. If X-ray is necessary:
   • Confirm pregnancy status for women of childbearing age (12-50 years)
   • Use appropriate shielding for the abdomen/pelvis
   • Optimize technique to minimize exposure
   • Document the justification for the examination
4. Post-procedure: Document estimated fetal dose if direct abdominal/pelvic imaging was performed

Common Pitfalls to Avoid

• Unnecessary avoidance of clinically indicated X-rays due to exaggerated perception of risk
• Failure to shield the abdomen during X-rays of other body parts
• Overlooking pregnancy status before performing high-dose procedures
• Using CT when ultrasound or MRI could provide adequate diagnostic information

Remember that the most effective way to limit radiation exposure to the pregnant patient is to carefully consider the indications and necessity for a particular examination, weighing the risks and benefits 1.