In which period of development are most organ system highly susceptible to injury?

Most organ systems are highly susceptible to injury during the embryonic period, which spans from conception to the end of the eighth week of gestation. During this time, critical processes such as organogenesis occur, making developing structures particularly vulnerable to teratogens, maternal health issues, and environmental factors. Disruptions in this period can lead to significant congenital anomalies and developmental disorders. After this phase, while the body continues to develop and mature, the susceptibility to injury generally decreases.