Your Baby’s Development at 20 Weeks

What Are My Baby’s Weight and Size at 20 Weeks?

You're halfway there! When you’re 20 weeks pregnant, your baby has grown a lot from that first dividing cell. At this point, babies weigh about 11 ounces (312 grams) and are about 6.3 inches (16 cm) long from the top of their head to their bottom.

Development Milestones at 20 Weeks

Your baby is taking up more room in your uterus (womb). As your baby keeps growing, there will be more pressure on your lungs, stomach, and bladder.

A waxy coating called the vernix covers and protects your baby’s skin as it gets thicker and develops layers. Your baby’s hair and nails keep growing.

Your Body When You’re 20 Weeks Pregnant

Pregnancy Symptoms at 20 Weeks

When you're 20 weeks pregnant, you might start to feel your baby move. This is called quickening and tends to happen between weeks 18 and 20. The movements might feel like a rumbling stomach or like there are “butterflies” in it. Later in pregnancy, you’ll feel your baby punch, kick, and maybe even hiccup. All babies move in different ways. If you're worried or notice less movement, talk with your doctor.

Now through the rest of your pregnancy, you’ll likely gain ½–1 pound (0.23 to 0.45 kilograms) each week.

Standard Appointments at 20 Weeks

20-Week Ultrasound

Even if you have already had a prenatal ultrasound, a test that uses sound waves to make an image, your doctor may want you to have a second-trimester ultrasound. This test can show the size and position of the baby in the womb, and any bone or organ problems that can be seen by this time.

Depending on your baby’s position, the doctor may be able to tell you the sex. The doctor will also look at the:

• placenta, the tissue that brings nutrients and oxygen to the developing baby
• umbilical cord, which connects the baby to the placenta
• amniotic fluid, the liquid the baby floats in within the amniotic sac. The fluid and sac cushion the baby in the mother's body and let the baby move and develop in the uterus

Ask your doctor if you should have an ultrasound at 20 weeks.