Final answer:
The embryonic stage is from weeks 3-8 after conception and is crucial for developing the body's organ systems. Exact figures for terminated embryonic stage conceptions vary, influenced by natural factors and technological practices like IVF regulations.
Step-by-step explanation:
The question relates to the embryonic stage of human development which is a key part of the gestation period. During this stage, the developing human is referred to as an embryo from weeks 3-8 following conception. It is a critical period where the foundational structures of the body's organ systems are formed. The exact number of conceptions terminated during the embryonic stage can vary and depends on natural factors and technological interventions such as IVF, which restricts the number of embryos to reduce the risk of multiple-birth pregnancies. The importance of prenatal care throughout these stages to reduce health risks both for the embryo/fetus and the parent is emphasized.