Second Trimester Baby Development


 

By now, your baby is sucking his finger, moving his arms and legs, and floating up and down. He may hear and respond to your voice, other voices and even music. He may be startled by other noises in your environment. We encourage you to talk to the baby (older brothers and sisters included), and play music for him. As your baby’s movements become strong enough for you to feel, you’ll begin to learn your baby’s patterns.

WEEK 14

Hair and eyebrows are growing. Heartbeat registers on ultrasound. Baby drinks amniotic fluid.

WEEK 15

Middle-ear bones harden and baby can hear for the first time.

WEEK 16

Fine hair (called “lanugo”), appears all over the body and face. External genital organs are visible with ultrasound.

WEEK 17

Fingernails and toenails begin to appear. Baby hears sounds outside the mother’s body and may jump when startled. Baby may also begin thumb-sucking.

WEEK 18

Baby measures 8 inches long, and is moving much of the time now.

WEEK 19

Buds for permanent teeth begin to form. Baby may get hiccups.

WEEK 20

Baby’s movements can now be felt by mother. Baby weighs between 8 and 16 ounces.

WEEK 21

Tongue is fully developed, and skin is becoming opaque.

WEEK 22

A greasy, white substance (known as “Vernix”) is beginning to form on the baby’s skin to protect it. (Most of this vanishes by birth.)

WEEK 23

Heartbeat is detectable by stethoscope.

WEEK 24

Lungs are immature, but other vital organs are developed enough for baby to survive outside the womb.

WEEK 25

Bone centers begin to harden.

WEEK 26

Fat stores are beginning to form.