Stages of Pregnancy: Week-by-Week Trimester Guide

How Many Stages of Pregnancy Are There?

Pregnancy is divided into three stages. These stages are called trimesters, and each one focuses on a different aspect of baby development.

First Trimester (Weeks 1–12): Early Stages of Pregnancy

During the first trimester, your body is building the support systems needed to nourish a fetus. Your body will produce extremely high levels of hCG as it builds the placenta that will pass nutrients to your baby.

Your stomach might not be noticeably larger yet, but pregnancy symptoms can be quite intense. Most women report morning sickness during this stage.

Second Trimester (Weeks 13–26): Growth and Stability

Your placenta is now strong enough to take over, so hCG levels will drop. This provides welcome relief from morning sickness for most people. 

The second trimester is often the stage when most people feel a little better. You might have more energy, and you'll start to feel the baby move. 

Third Trimester (Weeks 27–40): Final Stage of Pregnancy

By the third trimester, most of the essential organs and structures of the baby are developed. Your body will focus on building fat stores for the baby and fine-tuning organs. 

As the baby becomes larger and larger, you'll start to slow down and experience more pressure and discomfort in your torso. You may begin to feel cramps and other symptoms as your body prepares for labor.

Stages of Pregnancy Week by Week (Overview)

What are the stages of pregnancy for your baby? The first trimester involves the gradual change from a cluster of cells to a fully-formed embryo. The baby's heart, lungs, and other organs will form, and it will develop arms and legs. The baby will be almost three inches long by the end of the first trimester. 

In the second trimester, your baby will grow up to about 12 inches in length. During weeks 13 through 28, muscles, bones, and skin start to form. Your baby's body will begin to develop nerves, eyelashes, fingernails, and other fine details. You'll start to be able to feel your baby move around.

In the third and final stage of pregnancy, your baby gets much bigger. It will go from about one pound to six pounds in weight. During the third trimester, your baby will start to practice moving and breathing. By the end of the third trimester, your baby is ready to be born and meet you.

Signs and Symptoms Across Pregnancy Stages

Each trimester has its own distinctive symptoms. While the precise symptoms a pregnant person will experience vary, there are usually a few things most women will encounter. Here are typical pregnancy symptoms by stage:

• First trimester: Nausea, fatigue, food cravings, mood swings, headaches, and sore breasts

• Second trimester: Body aches, darkening skin, swollen hands and feet, numb hands, constipation

• Third trimester: Shortness of breath, hemorrhoids, tender breasts, difficulty sleeping, heartburn, swollen limbs, and uterine cramps

Navigating Each Stage with Support and Resources

Every stage of pregnancy can come with new challenges, so it's important to work with properly trained professionals. Research shows that support lowers your risk of prenatal depression, pregnancy complications, and more.

At Plana, we prioritize every aspect of pregnancy wellness at once. From symptom tracking to counseling, we're here for you. Our app provides a convenient place to get gentle, supportive advice and a customized care plan.

Conclusion

Pregnancy is an exciting time with a lot of changes for both you and your baby. Learn more details about the stages of pregnancy week by week by downloading the Plana app.