Diagnostic Ionizing Radiation in Pregnancy Reassessing Fetal Risk Thresholds and Addressing the Maternal Outcome Data Gap A Systematic Review

The methodical review of 10 sources (1989-2023) consolidates current evidence on the effects of ionizing radiation from diagnostic imaging on maternal and fetal health during pregnancy. The literature shows consistent agreement that fetal doses below 50 mGy pose minimal risk, with no evidence of increased lethality, genetic damage, teratogenicity, growth impairment, or sterility at this level. Deterministic effects, such as pregnancy loss, congenital malformations, growth retardation, and neurobehavioral abnormalities, have threshold doses of 100-200 mGy, which are significantly higher than typical diagnostic exposures. Common procedures, like ERCP, deliver fetal doses of 0.01-5.77 mGy, while abdominal CT scans average 10.8 mGy/100 mAs, both comfortably within safety margins. The 8-15 week gestational period is the most vulnerable to radiation effects, making timing considerations important when procedures can be postponed until the second trimester. A major limitation of current evidence is the almost complete lack of data on maternal outcomes, with only procedure-specific complications, like increased post-ERCP pancreatitis risk, being documented. Concerning stochastic effects, earlier studies indicated a higher risk of childhood cancer at any radiation dose, but newer research questions the linear no-threshold model, implying a lower carcinogenic risk at diagnostic doses than previously believed. This evidence supports the idea that clinically justified diagnostic imaging should not be avoided in pregnancy if the benefits outweigh the risks. Nevertheless, non-ionizing imaging methods should be prioritized when they provide equivalent diagnostic information. The ALARA principle should serve as the standard for all future radiation-based procedures. We retrieved 50 papers that were most relevant to the query.