What are the three trimesters of pregnancy called?

The three trimesters of pregnancy are commonly referred to as the first trimester, second trimester, and third trimester. This terminology is widely used in both medical and educational contexts to clearly delineate the stages of pregnancy, as each trimester corresponds to specific developmental milestones and physiological changes for both the mother and the fetus.

The first trimester encompasses weeks 1 through 12, when critical developments occur such as the formation of major organs and systems. The second trimester, from weeks 13 to 26, is often associated with further fetal growth and the establishment of a more rounded physical shape. Finally, the third trimester, from weeks 27 to the end of pregnancy, is characterized by significant weight gain and preparation for birth.

The other options describe trimesters with terms that are not commonly used in obstetrics and do not accurately reflect the established understanding and classification of pregnancy stages. This clear classification into three distinct trimesters helps healthcare professionals, fitness specialists, and expectant mothers to communicate effectively about pregnancy and related care.