What is a primary effect of radiation exposure during fetal development?

The primary effect of radiation exposure during fetal development is microcephaly. This condition is characterized by an abnormal smallness of the head and is often associated with developmental issues, including cognitive impairments. During the critical periods of brain development in the fetus, exposure to ionizing radiation can disrupt normal cellular processes, leading to incomplete or improper brain formation. The developing fetus is particularly sensitive to environmental insults, including radiation, and microcephaly serves as a significant indicator of potential neurodevelopmental damage caused by such exposure.

Other conditions like low birth weight, diabetes, and obesity may have associations with various environmental and genetic factors throughout life, but they are not directly linked to the teratogenic effects of radiation during the sensitive stages of fetal growth. Microcephaly, on the other hand, is a well-documented consequence of radiation exposure, leading to the classification of it as the primary concern for fetal development in this context.