Is a chest X-ray (CXR) safe for a pregnant patient presenting with chest pain or shortness of breath?

Chest X-Ray Safety in Pregnancy

Direct Answer

Chest X-ray is safe during pregnancy and should be performed without hesitation when clinically indicated for acute symptoms such as chest pain, shortness of breath, suspected pneumonia, or pulmonary embolism evaluation. 1

Radiation Exposure Context

The fetal radiation dose from a standard chest X-ray is extraordinarily low and poses no measurable risk:

• Fetal exposure is less than 0.01 mGy (0.00001 Gy), which is approximately 1/5,000,000th of the established safety threshold for fetal harm. 1
• The safety threshold for any detectable fetal harm begins at 50-100 mGy (50,000-100,000 μGy), with no measurable increased risk of prenatal death, malformation, or impaired mental development below 50 mGy. 2, 1
• This exposure is equivalent to only a few days of natural background radiation. 1

Clinical Decision Framework

The risk of missing a potentially serious maternal diagnosis far outweighs the negligible radiation risk from chest X-ray. 1

When evaluating pregnant patients with acute symptoms:

• Proceed immediately with chest X-ray for dyspnea, pleuritic chest pain, cough, suspected pneumonia, or suspected pulmonary embolism without delay. 2, 1
• Delaying or avoiding necessary imaging poses greater risk to both mother and fetus than the radiation exposure itself. 1
• Pulmonary embolism remains the leading cause of pregnancy-related maternal death in developed countries, accounting for 20% of maternal deaths in the United States. 2

Specific Clinical Scenarios

For suspected pulmonary embolism in pregnancy:

• Chest radiograph helps with risk stratification and is recommended as part of the diagnostic evaluation. 2
• If the patient has signs and symptoms of lower extremity DVT, perform bilateral compression ultrasound first—if positive, this confirms venous thromboembolism and treatment can begin without further imaging. 2
• Normal chest X-ray does not exclude PE but provides valuable diagnostic information. 2
• The American Thoracic Society/Society of Thoracic Radiology guideline explicitly supports chest radiography in pregnant women with suspected PE. 2

Technical Considerations

Modern evidence-based technique recommendations:

• Collimate the field to the area of interest to minimize fetal exposure. 1
• Abdominal/pelvic shielding for chest X-rays provides no meaningful benefit and may require repeat imaging if positioning is compromised—fetal exposure comes from scattered radiation from chest structures, not direct beam exposure. 1
• Document the clinical indication clearly in the medical record and note that risks and benefits were discussed with the patient. 1

Patient Counseling

When discussing chest X-ray with pregnant patients:

• Explain that the radiation dose is less than 0.01 mGy, which is 5,000 times lower than the safety threshold of 50 mGy. 1
• Frame the exposure as equivalent to a few days of natural background radiation. 1
• Emphasize that missing a serious maternal condition (such as pneumonia or pulmonary embolism) poses far greater risk than the negligible radiation exposure. 1
• Pregnant patients prefer radiation doses to be presented in comparison with known thresholds for fetal harm, using accessible language. 3

Critical Pitfalls to Avoid

• Never delay clinically indicated chest X-ray due to pregnancy—unnecessary anxiety leading to diagnostic delay poses greater harm. 1
• Do not rely on D-dimer to exclude PE in pregnancy—it has inadequate sensitivity (73%) and specificity (15%) with a negative likelihood ratio of 1.8. 2
• Do not use abdominal shielding for chest X-rays, as it provides no benefit and may compromise image quality. 1
• Chest radiography during first and second trimesters does not require pregnancy testing, as the fetal dose is negligible. 2

Additional Safety Information

• Diagnostic X-rays pose no risk to lactation, and breastfeeding does not need to be discontinued. 2
• Most diagnostic studies, including single-phase CT of the abdomen, deliver far less than 20 mGy to the uterus. 2
• Pregnancy testing within 72 hours is recommended only for fluoroscopic interventional procedures that may deliver doses above 100 mGy, not for standard chest radiography. 2