Second trimester: Your growing baby

The second trimester is a time for your baby to grow bigger and stronger.

By the end of the second trimester your baby will weigh about two pounds and measure about 12 inches from crown (top of the head)to rump (buttocks).

Your baby's gender can be identified in the fourth month. However, some babies don't provide a clear enough view during an ultrasound to tell for sure.

Although you can't feel it, your baby is very active. She can kick her legs, move her arms, turn her head and suck a finger or thumb. Your baby is also swallowing amniotic fluid, the fluid that surrounds her, and passing it as urine.

Although she is getting oxygen through the placenta and umbilical cord, your baby practices breathing movements. Her skin is now covered with a fine, downy hair called lanugo.

At about 20 weeks, earlier if you have already had a baby,you'll probably feel the first flutters of your baby's movements. This is called quickening. It will be several more weeks before family members will be able to feel your baby's movements.

During the fifth month, your baby's activity grows more coordinated. She can turn somersaults and make faces.

An ultra sound may show her frowning or grimacing. Your baby also has eyebrows and is growing hair. Her skin becomes covered with a protective, white coating called vernix.

By the end of the second trimester, your baby hears and responds to sounds. Loud noises may startle her, making her move. She is listening to your voice and will recognize it after she is born.

She will recognize the voices of other family members, too. Each of you can sing or play a song that is "your song." Your baby will recognize it after birth and quiet when she hears it.

Your baby is also opening and closing her eyes and reacting to light. She can make a fist and grasp the umbilical cord. You may feel her pushing her feet against the wall of your uterus as if she is walking. The rhythmic movements you sometimes feel are hiccups.

Baby's development: Weeks 14 to 26

Week 14

Your baby's hair and eyebrows are growing. His or her heartbeat is strong enough to hear with ultrasound.

Week 15

Your baby's middle ear bones have harden, so he or she can hear.

Week 16

Your baby's skin is now covered with a fine, downy hair called Lanugo. Baby's external genital organs (girl or boy) are developed enough to be seen with ultrasound. Your baby’s gender can be identified in the fourth month. However, some babies don’t provide a clear enough view during an ultrasound to tell for sure.

Week 17

Your baby can hear and respond to sound. Loud noises may startle your baby making him or her move. Your baby is listening to your voice and will recognize it after he or she is born. He or she will recognize the voices of other family members, too

Week 18

Your baby is about 8 inches long and is moving much of the time now. He or she can kick his or her legs, move his or her arms, turn his or her head, and suck a finger or thumb. Your baby's Fingernails and toenails also begin to appear.

Week 19

Your baby is swallowing amniotic fluid, the fluid that surrounds him or her, and passing it as urine. Baby may get hiccups. Buds for permanent teeth are beginning to form.

Week 20

You’ll probably feel the first flutters of your baby’s movements. This is called quickening. Your baby is about 8 1/2 inches long and weighs 8 to 16 ounces.

Week 21

Your baby's skin is becoming opaque. His or her tongue is fully developed.

Week 22

Your baby's skin becomes covered with a protective, white coating called vernix. Most of the vernix will disappear before birth.

Week 23

Your baby's heartbeat might be able to be heard with a stethoscope.

Week 24

Vital organs are developed enough for your baby to survive outside the womb. Lungs are immature, however, and your baby would need breathing assistance if born now.

Week 25

Your baby's bone centers beginning to harden.

Week 26

Your baby's body fat is beginning to form.

Source: Allina Health's Patient Education Department, Beginnings: Pregnancy, Birth and Beyond, seventh edition, ob-ah-90026
First Published: 10/04/2002
Last Reviewed: 12/02/2015

Tips to help you choose a pregnancy care provider