How many equal time periods are pregnancies divided into?

Pregnancies are typically divided into three equal time periods known as trimesters. Each trimester lasts approximately three months, leading to a total gestation period of about nine months. The three trimesters are used as a framework for understanding the developmental stages of pregnancy.

In the first trimester, which covers weeks 1 to 12, essential developments occur, including the formation of major organs and structures. The second trimester spans weeks 13 to 26 and is often when the fetus grows rapidly, and many women experience fewer pregnancy symptoms. The third trimester, from weeks 27 to 40, is focused on the final growth and preparation for birth.

Understanding these three distinct trimesters is crucial for monitoring fetal development, maternal health, and preparing for childbirth. Each trimester also corresponds with different prenatal care guidelines and screenings.