Can a chest X-ray (CXR) be performed during the 2nd trimester of pregnancy?

Chest X-Ray in Second Trimester Pregnancy

Yes, you can and should perform a chest X-ray during the second trimester of pregnancy when clinically indicated—the fetal radiation exposure is less than 0.01 mGy, which is approximately 1/5,000,000th of the safety threshold for fetal harm (50-100 mSv). 1

Radiation Safety Context

The radiation exposure from a chest X-ray during pregnancy is extraordinarily low and poses negligible risk:

• Fetal dose from chest X-ray: <0.01 mGy 2, 1
• Established safety threshold for fetal harm: 50,000-100,000 mGy (50-100 mSv) 1
• This represents less than 1/5,000,000th of the harmful dose threshold 1

The European Society of Cardiology explicitly states that chest radiographs should be obtained when clinically necessary, as the radiation dose is negligible compared to the potential consequences of missing serious maternal conditions. 2, 1

Clinical Decision Framework

Proceed with chest X-ray without hesitation when clinically indicated for:

• Dyspnea or respiratory distress 2, 1
• Persistent cough requiring evaluation 2, 1
• Suspected pneumonia 1
• Evaluation for pulmonary embolism (though CT may ultimately be needed) 2, 3
• Any acute respiratory symptoms requiring diagnostic clarification 1

The risk of missing a potentially serious maternal diagnosis far outweighs the negligible radiation risk to the fetus. 1 Delaying or avoiding necessary imaging poses greater risk to both mother and fetus than the radiation exposure itself. 1

Evidence-Based Safety Data

Multiple high-quality guidelines confirm the safety profile:

• The European Society of Cardiology (2011) documents that chest radiographs deliver <0.01 mGy to the fetus, well below any threshold for concern 2
• Research demonstrates that diagnostic radiation procedures not involving direct abdominal/pelvic exposure are not associated with significant adverse events 4
• The only statistically proven adverse effect at diagnostic radiation levels is an extremely small increase in childhood malignancy risk (one additional cancer death per 1,700 exposures at 10 mGy—100 times higher than chest X-ray dose) 4

Common Pitfalls to Avoid

Do not delay necessary chest imaging due to unfounded radiation anxiety:

• Counsel patients that chest X-ray radiation is equivalent to a few days of natural background exposure 1
• Emphasize that missing a serious maternal condition (pneumonia, pulmonary embolism, cardiac disease) poses far greater risk than the imaging itself 1
• Document the clinical indication clearly in the medical record and note that risks and benefits were discussed 1

Regarding abdominal shielding:

• Modern evidence indicates that abdominal shielding for chest X-rays provides no meaningful benefit for fetal protection 1
• Shielding may compromise image quality and require repeat imaging, potentially increasing total radiation exposure 1
• Fetal exposure from chest X-ray comes from scattered radiation within the chest, not direct beam exposure to the abdomen 1

Technical optimization:

• Collimate the field to the area of interest to minimize scattered radiation 1
• Ensure proper positioning to avoid direct radiation exposure to the abdomen and pelvis 1
• Follow the ALARA principle (as low as reasonably achievable) for all radiation exposures 2

Documentation Recommendations

When ordering chest X-ray in pregnancy:

• Document the specific clinical indication requiring imaging 1
• Note that the patient was counseled about negligible fetal risk 1
• Record that the benefits of diagnosis outweigh minimal radiation exposure 1