Tests, appointments, physical changes – a lot happens during the first trimester (0-14 weeks) of pregnancy. Here's some information that can help you through those first important months.

Your first trimester lasts from week 1 to end of week 14.

• Normal Pregnancy: First Trimester
• Your First Trimester - Video

Babies grow quickly during the first trimester. Learn about the two stages of development and how your baby’s growth will progress:

• Embryo and Fetal Development In the First Trimester
• Fetal development at 12 weeks of pregnancy
• Fetal development at 8 weeks of pregnancy
• Week 8 of Pregnancy: What's Going On Inside
• Week 12 of Pregnancy: What's Going On Inside

Having regular prenatal care is important while you are pregnant. Early in your pregnancy, you can expect to visit your doctor or midwife every four to six weeks.

• Check-ups and Tests In the First Trimester
• Medical Care During the First Trimester

You may feel tired, gain weight or have mood changes during the first trimester. This is normal. Learn more about other changes to expect:

• Changes During the First Trimester of Pregnancy Weeks 0-14
• Mothers' Physical Changes in the First Trimester
• Pregnancy Weight Gain In the First Trimester

Some women experience morning sickness in the first trimester. Morning sickness includes nausea, sometimes with vomiting, caused by hormones released by a woman's body during pregnancy. It occurs most often during the first three months of pregnancy. Symptoms can occur at any time of the day or night. If you have severe, ongoing nausea and vomiting (hyperemesis gravidarum), see your health care provider for treatment. This uncommon complication of pregnancy can lead to dehydration. You may need prescribed medicines, hospitalization, or both.

Last Updated: June 2021