Week by Week Pregnancy

Week by Week Pregnancy Processes

Each of your experiences as pregnant is grouped into trimesters with medical milestones for both you and your baby.

First Quarter

The baby grows rapidly during the first trimester (weeks 1 to 12). The fetus begins to develop its brain, spinal cord and organs. The baby’s heart also begins to beat.

The probability of miscarriage in the first trimester is relatively high. According to the American College of Obstetricians and Gynecologists (ACOG), about 1 in 10 pregnancies are estimated to have miscarriages, and about 85 percent of these occur in the first trimester.

If you think you are experiencing symptoms of miscarriage, seek help immediately.

Second Trimester

During the second trimester of pregnancy (weeks 13 to 27), your doctor will most likely order an ultrasound.

This test checks the fetus’s body for developmental abnormalities. Test results can also reveal your baby’s gender if you want to know before the baby is born.

You will likely begin to feel your baby moving, kicking and punching in the womb.

After 23 weeks, a baby is considered “viable” in utero. This means it can continue to live outside of your womb. These preterm babies often have serious medical problems. The longer your baby can carry your pregnancy, the better your chances of being born healthy.

Third Quarterly

In the third trimester (weeks 28 to 40), your weight gain accelerates and you may feel more tired.

Your baby can now perceive light and open and close their eyes. Bones are also formed.

As labor approaches, you may feel pelvic pain (sudden onset, intense pain) and your feet may swell. Non-delivery contractions, known as Braxton-Hicks contractions, can begin to occur in the weeks before delivery.

Summary Information

Every pregnancy is different, but improvements will most likely occur within this general time frame. Learn more about the changes you and your baby will go through during the trimester.

Source: Healthline, What Do You Want to Know About Pregnancy?, 2019.


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