When does major organogenesis occur during pregnancy?

Major organogenesis refers to the critical period during which the major organs and systems of the developing fetus begin to form. This crucial phase occurs primarily between the third and eighth weeks of gestation, but the most significant development, particularly in the context of the major organs, occurs from the end of the second week through the tenth week.

During this time frame, the foundations of vital organs such as the heart, brain, kidneys, and lungs are established. Because organogenesis is such a complex and sensitive process, any potential risk to the developing fetus, including exposure to radiation, can have significant consequences. Therefore, understanding the timing of organogenesis is essential for ensuring that pregnant individuals are protected from unnecessary radiation exposure during this critical period.

While the first week can include fertilization and initial cell division, it is too early for organ development to be considered organogenesis. Similarly, the weeks following the tenth week are more focused on growth and maturation rather than the formation of the organs themselves. Thus, recognizing the timeframe that encompasses the critical stages of organ development is vital in minimizing risks associated with radiation exposure during pregnancy.