Week-by-Week Pregnancy Guide

Knowing what to expect during each stage of pregnancy can help reduce the stress and anxiety associated with having a baby. Read our week-by-week pregnancy guide to learn more about the symptoms moms-to-be can expect to experience during each trimester, as well as the weekly stages of normal fetal growth and development.

Trimester One - The First Half

During weeks one through six of the first trimester of pregnancy, women typically begin experiencing pregnancy symptoms as the embryo implants itself and the fetus slowly begins to develop.

Trimester One - The Second Half

During the second half of the first trimester of pregnancy, the fetus' facial features, fingers, and toes begin to take distinct shapes. By the end of the 12th week of pregnancy, nausea and other symptoms begin to diminish.

Trimester Two - The First Half

The beginning of the second trimester marks the approximate time that pregnant women begin to show. As the fetus develops, it will generally begin to kick, make facial expressions, and hear during the first half of trimester two.

Trimester Two - The Second Half

By the end of the second trimester, the fetus is able to taste and touch, and the eyes become fully developed. The fetus also begins to practice breathing. At this point in the pregnancy, women can expect to gain about four pounds a week until the baby is born.

Trimester Three - The First Half

The third trimester of pregnancy generally becomes a bit more uncomfortable for pregnant women, as the baby will weigh four to five pounds by week 34. During the first half of the third trimester, the fetus will open its eyes and detect light, and the lungs will be almost fully developed.

Trimester Three - The Second Half

By the end of week 37 the fetus is considered full-term, although projected due dates estimate the pregnancy will last 40 weeks. This period tends to be the most uncomfortable for expectant mothers, and many experience frequent urination, trouble sleeping, heartburn, and lower back pain.