Is a chest x-ray (CXR) safe during pregnancy?

Chest X-Ray Safety During Pregnancy

Yes, chest x-ray is safe during pregnancy—the fetal radiation exposure from a standard two-view chest x-ray is only 0.00007 rad (0.0007 mGy), which is negligible and poses no measurable risk to the developing fetus. 1

Radiation Dose Context

The radiation exposure from chest radiography is extraordinarily low compared to safety thresholds:

• Accepted cumulative dose limit during entire pregnancy: 5 rad (50 mGy) 1
• Actual fetal exposure from chest x-ray: 0.00007 rad (0.0007 mGy)—approximately 70,000 times lower than the pregnancy limit 1
• Threshold for any detectable fetal harm: 100 mGy 2
• Threshold for serious effects (mental retardation): Above 100 mGy 2
• Threshold for malformations: Exceeds 150 mGy 3

No single diagnostic radiographic study exceeds the maximum acceptable cumulative dose for pregnancy. 1

Clinical Application

When chest x-ray is medically indicated during pregnancy:

• Perform the study without hesitation when clinically necessary (e.g., suspected pneumonia, tuberculosis evaluation) 2, 4
• Use abdominal shielding to further minimize already negligible fetal exposure 2
• Chest x-ray is appropriate at any gestational age, including first trimester, given the minimal exposure 1, 4
• The benefit of accurate diagnosis far outweighs the negligible radiation risk in symptomatic patients 4, 5

Timing Considerations

While the most sensitive period for central nervous system teratogenesis is 10-17 weeks gestation, this concern is only relevant for high-dose exposures (>100 mGy). 1 For chest x-ray specifically, the dose is so low that timing is clinically irrelevant—perform when indicated regardless of gestational age. 1, 5

Risk Perspective

The only statistically proven adverse effect at diagnostic radiation levels is a very small increase in childhood malignancy:

• Estimated risk: One additional cancer death per 1,700 exposures at 10 mGy 5
• Chest x-ray delivers approximately 0.0007 mGy to the fetus—roughly 14,000 times lower than this reference dose 1
• This risk is negligible compared to baseline pregnancy risks and the risk of missing maternal pathology 1, 6, 5

Common Pitfalls to Avoid

• Do not delay necessary chest imaging due to pregnancy concerns—the radiation exposure is trivial and diagnostic delay poses greater risk 4, 5
• Radiation exposure from chest x-ray is NOT an indication for pregnancy termination or additional fetal monitoring 1
• Do not substitute less appropriate imaging modalities (like MRI for pneumonia evaluation) simply to avoid radiation when chest x-ray is the optimal diagnostic test 4

Patient Counseling

Appropriate counseling before the study is critical: Explain that chest x-ray delivers less radiation to the fetus than natural background radiation exposure over a few days, and that the study poses no measurable risk to the pregnancy. 1, 5 This prevents unnecessary anxiety and ensures informed consent.