{Reference Type}: Journal Article {Title}: Prenatal X-ray Exposure and the Risk of Developing Pediatric Cancer-A Systematic Review of Risk Markers and a Comparison of International Guidelines. {Author}: Wit F;Vroonland CCJJ;Bijwaard H; {Journal}: Health Phys {Volume}: 121 {Issue}: 3 {Year}: 09 2021 1 {Factor}: 2.922 {DOI}: 10.1097/HP.0000000000001438 {Abstract}: Since the first Oxford Survey of Childhood Cancer's results were published, people have become more aware of the risks associated with prenatal exposure from diagnostic x rays. As a result, it has since been the subject of many studies. In this review, the results of recent epidemiological studies are summarized. The current international guidelines for diagnostic x-ray examinations were compared to the review. All epidemiological studies starting from 2007 and all relevant international guidelines were included. Apart from one study that involved rhabdomyosarcoma, no statistically significant associations were found between prenatal exposure to x rays and the development of cancer during 2007-2020. Most of the studies were constrained in their design due to too small a cohort or number of cases, minimal x-ray exposure, and/or data obtained from the exposed mothers instead of medical reports. In one of the studies, computed tomography exposure was also included, and this requires more and longer follow-up in successive studies. Most international guidelines are comparable, provide risk coefficients that are quite conservative, and discourage abdominal examinations of pregnant women.