The First Trimester: What to Expect

You're pregnant — congratulations! This is the beginning of an exciting journey.

Pregnancy usually is measured by weeks, and a typical pregnancy lasts 40 weeks. Those weeks are grouped into trimesters.

The first trimester starts on the first day of your last menstrual period (yep — your last period is actually counted as your first week of pregnancy) and ends at 13 weeks and 6 days of pregnancy. During the first trimester, your baby's major organs, limbs, parts of the face and eyelids start to develop. You’ll provide the nutrition and energy to grow baby from a small cluster of cells to about the size of a kiwi — and that’s a lot of work! Here’s what you can expect.

Early-pregnancy changes

At this stage, your body starts going through significant changes to nourish baby's growth and to prepare for labor and delivery. You'll feel changes, both physical and mental.

“Every pregnancy is different,” says Michelle Wheeler, MD, OB/GYN at Adventist Health Portland. “Not every pregnant person experiences the same things — and each pregnancy can vary quite a bit for the same person. Always ask your provider if you’re concerned about new or worsening pregnancy symptoms.”

Typically, you can expect:

Fatigue. As your body becomes accustomed to supporting a new life, you'll feel very tired. Be sure to get enough sleep at night and take naps as needed. Fatigue often lessens during the second trimester.

Morning sickness. Pregnancy hormones can cause nausea and vomiting. Things that once smelled and tasted good may suddenly upset your stomach. Like fatigue, morning sickness usually disappears in the second trimester. Eating a snack can actually help nausea for some people — especially bland foods like crackers, bread and butter, or pasta.

“If you can’t keep anything down and you’re too sick to function, tell your provider,” says Dr. Wheeler. “You may have hyperemesis gravidarum, a severe form of morning sickness that causes excessive vomiting. Your provider can offer antinausea medications to help you manage.”

Heartburn, indigestion and constipation. Pregnancy hormones can slow down digestion. This is, in part, to give your body more time to absorb nutrients for your baby. You may also notice gas and bloating.

Breast changes. Your breasts will start to become larger, and they will feel swollen and sensitive. Some women notice breast tenderness before they even know they’re pregnant.

Light-headedness. Your body is creating more blood for the baby. This could make you feel dizzy or lightheaded. Always be sure to sit down when you feel dizzy, and drink plenty of water and eat small snacks throughout the day.

Choose a provider

As soon as you know you're pregnant, it's important to choose a provider and receiving prenatal care. Generally, pregnancy care is provided by a doctor (an OB/GYN) or a certified nurse-midwife.

An OB/GYN is a doctor who specializes in pregnancy and delivery, including cesarean section when necessary. A certified nurse-midwife is a registered nurse with master’s degrees and special clinical training in women’s care and birthing. Both OB/GYNs and midwives provide prenatal care and delivery babies at Adventist Health Portland. Not sure which is right for you? This guide can help.

Schedule prenatal visits

You will visit your provider throughout your pregnancy — with your first appointment usually around week 7 or 8. You’ll typically see your provider monthly during your first trimester, twice monthly during your second trimester and weekly at the end of your pregnancy.

“Throughout pregnancy, your provider will examine you and do screenings and tests to help make sure you and your baby are as healthy as possible,” says Dr. Wheeler. “Visits will include either listening to the baby’s heartbeat with a handheld doppler, or we may perform ultrasounds to see the baby. Some visits may also include bloodwork.”

At each visit, you and your provider will discuss all aspects of your pregnancy, including labor and delivery. If you find yourself with lots of questions, jot them down so you can ask at your next appointment.

Care for pregnancy, birth and beyond

Our doctors and certified nurse-midwives value the chance to partner with you as grow and welcome your little one. They combine extensive specialized training with a deep understanding of and compassion for women’s individual needs.

Prenatal care is available at our women’s clinics in Clackamas and Portland. Meet our team or call (503)261-4423 to schedule an appointment.