What is the term for the 3-month segments in the development of a fetus?

The term used for the 3-month segments in the development of a fetus is "trimesters." This term is commonly used in obstetrics to describe the three distinct phases of gestation, where each trimester corresponds to approximately three months of pregnancy. The first trimester includes conception to 12 weeks, the second extends from 13 to 26 weeks, and the third from 27 weeks until birth.

Understanding this terminology is crucial in the context of prenatal care and fetal development, as it helps healthcare providers track growth, diagnose potential issues, and communicate effectively with expectant parents about the stages of pregnancy. Each trimester is marked by significant developmental milestones in the fetus, which are important for both medical assessments and the preparation of parents for the upcoming stages of pregnancy and childbirth.