What to expect in your first trimester

While some of the symptoms and changes may be less than exciting, just remind yourself that you’re growing a human – and that’s amazing!

You may never be fully prepared, but knowing what to expect can help you get ready for the months ahead. Here’s what you can expect during these early weeks in your pregnancy.

How long is the first trimester?

The first trimester lasts from week 1 through the end of week 13 (or months one through three). During this time, lots of changes are happening as your body prepares and begins to host your little bundle of joy for the next nine months.

Your baby’s growth and development

During the first trimester, your baby develops from a single fertilized cell (called a zygote) to a lemon-sized fetus of (quickly) growing limbs and organs. You may not be able to feel it yet, but your baby will even start to move in these early weeks. Here are a few first trimester development milestones for your baby:

• Eyes – Optic nerves and lenses will begin to form by week 4.
• Heart – Around week 5, the tube that will develop your baby’s heart will begin to beat. It’ll become stronger and you may be able to hear it later in your first trimester.
• Bones – Around week 6, your baby will start to grow arms, legs, hands and feet. Fingers and toes will start to grow at about week 10.
• Skin, hair and nails – Your baby’s skin will begin forming between weeks 5 and 8. His or her hair follicles and nail beds will develop around week 11.
• Brain – Your baby’s neural tube (forming his or her spinal cord and brain) is in place by week 5. By week 8, his or her brain will begin moving those tiny developing limbs.

Pregnancy symptoms and body changes during your first trimester

If you’ve talked to friends or relatives who have been pregnant, you know that pregnancy is different for every woman. Here’s some common symptoms and changes you may experience: 

• Morning sickness - Morning sickness can strike any time of the day and usually eases up around your second trimester. Eating smaller, more frequent meals, ginger tea or acupressure can help, but if your morning sickness is severe, talk to your doctor about medications to help your nausea.
• Tender breasts - Around week 6, you may begin noticing some big changes in your breasts – they’re tender and growing.
• Food aversions - Unfortunately, you may find that you just can’t stand the smell, taste or look of foods you once loved. During this time, stick to foods you can stomach.
• Mood swings - Mood swings are common in early pregnancy. If you have a history of depression or you’re concerned about your mood swings, talk to your doctor.
• Fatigue - A lot of your energy is being used to help your baby grow and develop, because of this, you may feel more tired than usual. Try to get a good night’s rest and take naps when you need them.
• Weight gain – During your first trimester, your baby is very small, so you’ll only gain about three to four pounds. If you’re suffering from morning sickness, you may lose weight – this is perfectly fine.
• Food cravings – You may be feeling extra hungry. If so, try to keep your caloric intake in check as best as you can. If you end up gaining more weight than is recommended, that’s okay – just try to get yourself back on track.

Other symptoms and changes you may experience

As you progress through your first trimester, you may experience additional symptoms such as frequent urination, heartburn, constipation, metallic taste and headaches. Hang in there, mama – the second trimester will bring some welcome relief!

Pregnancy symptoms to call your doctor about

In most cases, odd symptoms aren’t cause for concern; however, it’s important to pay attention to your symptoms and seek medical help right away if you experience any of the following:

• Severe abdominal pain and/or cramping
• Heavy vaginal bleeding
• Sudden thirst 
• Painful urination
• Backache, chills or fever higher than 101.5 degrees

Prenatal care during your first trimester

After you get that positive pregnancy test, you’ll want to schedule your first prenatal appointment. Whether you choose an OBGYN or midwife, prenatal care can help you have the healthiest pregnancy possible.

Prenatal visits during your first trimester are typically scheduled every four weeks. During these first few visits, you doctor will perform blood tests, physical exams and address any questions or concerns you may have.

You’ll also want to make sure you are:

• Taking prenatal vitamins
• Eating a healthy, balanced diet
• Getting at least 30 minutes of activity in each day
• Stopping use of alcohol and/or tobacco