Over the past few decades, CT scans have become a mainstay of modern medicine, providing fast, detailed images that can be critical for diagnosis and treatment. Because these scans use low doses of ionizing radiation, their increasing use has prompted researchers to look more closely at their long-term effects, including on reproductive health.
Now, a new study led by Dr. Camille Simard, Assistant Professor of Medicine at 91黑料网 and specialist in Obstetric Medicine at the Jewish General Hospital, published in the , adds new insight by examining whether imaging before pregnancy could have any effect on reproductive outcomes.
To explore this question, Dr. Simard and her team analyzed data from more than five million recognized pregnancies in Ontario, making it one of the largest studies to date on the possible effects of low-dose radiation exposure in the years before conception.
鈥淲e were motivated to pursue this research because while the effects of high dose radiation, such as from radiotherapy or atomic bomb exposure, are well described, very little is known about the potential impact of lower dose exposures, like CT scans, in the years before conception.鈥� said Dr. Simard. 鈥淲ith the increasing use of these imaging modalities, we wanted to explore whether such exposures could meaningfully affect pregnancy outcomes.鈥�
The researchers found that women who had undergone CT scans before pregnancy experienced slightly higher rates of pregnancy loss and congenital anomalies compared with those who had not been exposed. The risks increased with the number of CT scans and were highest when exposure occurred closer to conception. Scientists believe this may be linked to how ionizing radiation can damage the ovarian follicles that contain egg cells, potentially affecting their DNA long before conception.
While these findings don鈥檛 call for alarm, they highlight the importance of using imaging wisely, especially for women of childbearing age. CT scans have become a cornerstone of modern medicine, particularly in emergency and acute care settings, where fast and accurate diagnosis can save lives. But as their use grows, understanding even small potential risks becomes part of responsible medical practice.
鈥淲e must uphold the principle of 鈥榝irst, do no harm,鈥� exercising careful clinical judgment to avoid unnecessary radiation exposure while ensuring that essential imaging is never withheld,鈥� she said.
Dr. Simard believes that future research should look more closely at how the timing of CT exposure influences the risk of adverse pregnancy outcomes. 鈥淚n our study, the risks were greatest when CT occurred closer to conception, suggesting that radiation exposure to the ovaries may have different effects depending on when it occurs. Refining this timing could help clarify the underlying mechanisms and ultimately guide more nuanced recommendations for imaging in women of reproductive age,鈥� she said.
Funded by the Canadian Institutes of Health Research, the study contributes to a broader discussion about women鈥檚 health, fertility, and the safe use of medical technology, topics that have become increasingly relevant as more Canadians choose to start families later in life.
Publication: Annals of Internal Medicine
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Authors: Camille Simard MD MSc, Longdi Fu MSc, Tomi Odugbemi MSc, Andrea N. Simpson MD MSc, Jun Guan MSc, Vicky Tagalakis MD MSc, Aur茅lien Delluc MD PhD, and Joel G. Ray MD MSc