Are airport body scanners safe during pregnancy?

What does the evidence say about airport body scanners during pregnancy?

1. Women who are pregnant or breastfeeding a child can use body scanners at airports. 1
2. In the United States, airport body scanning units do not use ionizing radiation. These machines use millimeter wave technology to scan a person's body instead. 2
3. Independent scientific review of active millimeter wave security scanning systems describes them as operating at roughly 30 GHz, a non-ionizing radiofrequency, with low power densities incident on the body during a scan. 3
4. Ionizing radiation, the category that includes medical x-rays and gamma rays, carries enough energy to remove electrons from atoms; non-ionizing energy doesn't reach that threshold, which is the underlying physics behind why safety guidance separates the two categories so clearly. 4
5. Millimeter-wave technology is described as non-ionizing radiation in the form of low-level radio waves, the same broad energy category as radio and wifi signals rather than the ionizing category used in diagnostic imaging. 1

Is airport body scanners safe in each trimester?

• First trimester. Early pregnancy travel goes through the same screening as everyone else. Millimeter wave scanners fall into the non-ionizing category, so the theoretical radiation concerns that make people cautious about actual x-ray imaging don't apply here regardless of how far along you are.
• Second trimester. Many people do the bulk of their pregnancy travel in the second trimester. The technology classification doesn't change with gestational age, so a scanner pass at 14 weeks and one at 24 weeks carry the same non-ionizing exposure profile.
• Third trimester. Standing still with arms raised for a few seconds can just feel more awkward with a full-term belly. That's a comfort issue, not a safety one, and a pat-down is always available if you'd rather skip the posture.