Preconception CT Exposure Raises Risk for Pregnancy Loss

Risks associated with ionizing radiation received during pregnancy are well characterized, but such data are not available for exposure before conception. Using population-based Canadian data, researchers evaluated preconception exposure to ionizing radiation from computed tomography (CT) scans and rates of spontaneous pregnancy loss (miscarriage, ectopic pregnancy, or stillbirth) and congenital anomalies among five million women with recognized pregnancies.

The primary exposure was the cumulative number of CT scans performed at least 4 weeks before the estimated date of conception. Almost 700,000 women received such scans.