Infographics / Radiation Protection

Gestational timeline of in-utero radiation effects

A timeline of gestational age in weeks after conception showing when each in-utero radiation risk is greatest. Foetal death peaks in the pre-implantation window (0 to 2 weeks, all-or-none). Malformations peak during organogenesis (3 to 8 weeks). Reduced IQ and central nervous system effects peak at 8 to 15 weeks. Growth retardation is greatest across the foetal period, 8 to 25 weeks. These deterministic effects have a threshold around 100 to 200 mGy and worsen with dose. Childhood cancer is stochastic, has no threshold, and can follow exposure at any stage, shown as a dashed bar spanning the whole pregnancy.

Foetal radiation effects by gestational age A timeline of gestational age in weeks after conception showing when each in-utero radiation risk is greatest. Foetal death peaks in the pre-implantation window (0 to 2 weeks, all-or-none). Malformations peak during organogenesis (3 to 8 weeks). Reduced IQ and central nervous system effects peak at 8 to 15 weeks. Growth retardation is greatest across the foetal period, 8 to 25 weeks. These deterministic effects have a threshold around 100 to 200 mGy and worsen with dose. Childhood cancer is stochastic, has no threshold, and can follow exposure at any stage, shown as a dashed bar spanning the whole pregnancy. Foetal radiation risk by gestational age weeks after conception 0 2 8 15 25 38 term Foetal death pre-implantation, all-or-none Malformations organogenesis Reduced IQ CNS, peak radiosensitivity Growth retardation foetal period Childhood cancer stochastic, no threshold Solid bars: deterministic effects, threshold about 100 to 200 mGy, severity rises with dose. Dashed bar: childhood cancer is stochastic, no threshold, risk at any stage of pregnancy.
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