You are officially halfway through your pregnancy. The fetus now has all its organs, muscles, and limbs in place. From here on, the focus is on growth, weight gain, and maturation. The anatomy scan, if not done yet, typically happens this week.
Your Baby This Week
Size: Banana (about 16.5 cm crown to rump, or 25 cm head to toe)
Weight: About 300 grams
Starting this week, the fetus is measured from head to toe instead of crown to rump, because the legs are now extended rather than curled up.
- Swallowing practice: The fetus swallows several ounces of amniotic fluid daily, training the digestive system
- Meconium: Building up in the intestines. This dark, tarry substance will be the baby's first bowel movement after birth.
- Sleep-wake cycles: Becoming more defined. You may notice the baby is most active at certain times of day.
- Skin layers: The dermis, epidermis, and subcutaneous layer are all present
- Immune system: The spleen is producing white blood cells
- Taste preferences: Studies show that the baby swallows more amniotic fluid when it tastes sweet and less when it tastes bitter
Your Body
- Fundal height. Your uterus has reached your navel. From now on, your provider will measure the fundal height (the distance from pubic bone to the top of the uterus) at each visit. At 20 weeks, it should be about 20 cm.
- Belly button changes. Your innie may start to pop out as the uterus pushes from behind. This is normal and temporary.
- Shortness of breath as the uterus pushes upward against the diaphragm
- Leg cramps continue, especially at night
- Strong kicks and rolls that may be visible from the outside
What to Do This Week
- Attend your anatomy scan if scheduled. Bring your partner or a support person. This is often an emotional appointment, as you get a detailed look at your baby's face, hands, heart, and spine.
- Start researching childbirth classes. Whether you prefer hospital-based education, Lamaze, hypnobirthing, or online courses, now is a good time to sign up.
- Celebrate the halfway point. Some families have a gender reveal, a babymoon trip, or simply a special dinner. You have earned it.
Common Questions
What if the anatomy scan finds something?
Most anatomy scans come back perfectly normal. If the sonographer flags something, try to stay calm. Some findings are minor variations that resolve on their own. Others may require additional testing or monitoring. Your provider will explain what was found and the recommended next steps.
How big will my baby get from here?
At 20 weeks, the baby weighs about 300 grams. By 40 weeks, the average newborn weighs about 3,400 grams (7.5 pounds). That means most of the weight gain happens in the second half of pregnancy, especially in the third trimester.