Baby's Development: Second TrimesterKnow what's happening with your baby as he continues to grow in your belly!
- Week 13
The baby’s eyes and ears are moving closer to their final positions. The liver is secreting bile; the pancreas is producing insulin; the vocal cords are forming; and what will be later known as “baby teeth” are already positioned in the gums.
Your baby is at least three and a half inches long. Lung power gains momentum as your baby “breathes” amniotic fluid in and out.
The body is now more proportionate to the head. Your baby has started thumbsucking. The skin is covered with lanugo—soft, velvety hair that protects the fetus until birth.
Expect some painless contractions every now and then for two reasons: one, your baby begins to “hiccup” quietly, and two, your baby’s bones are hardening, causing his fully functional joints to jerk. Facial muscles are developing.
Your baby is roughly the size of an avocado, and has pink, transparent skin. The major organs are in full swing. The heart is pumping approximately 25 quarts of blood a day.
The ears have reached their final position, and the eyes are now looking forward. You will feel swift jerks as your little one becomes more active. The baby’s skeleton is still soft and pliable, while the brain is growing fast.
Skin is thicker, whitish, and covered with a creamy translucent moisturizer called vernix caseosa. Brown fat deposits begin to accumulate underneath the baby’s skin to help stabilize body temperature.
If you have a girl, her uterus is now developing. Your baby is now taking on a typical newborn’s sleeping patterns.
Your baby’s bone marrow starts helping the liver and spleen produce blood cells.
Your baby’s senses of taste and touch have started to develop. If you have a boy, the testes are now descending from the pelvis to the scrotum. If you have a girl, the vagina has developed and the uterus and ovaries are in position.
The lungs are starting to develop.
The lungs are preparing for the initial secretion of surfactant, a fatty substance that will coat the inner lining of the air sacs. Surfactant keeps air sacs in the lungs from sticking together when your baby exhales outside the womb for the first time.
Your baby is growing more rapidly. The spine and the blood vessels of the lungs are beginning to form. The nostrils have started to open, and the bones are continuing to harden (ossification).
The air sacs are finally forming this week, and the lungs are already beginning to secrete surfactant. You can also see your baby’s veins through his or her skin.
You might feel more “filled up” since your baby is around 14.4 inches long (with legs extended). Neural connections are firing up. The lungs, liver, and immune system are still undergoing further development.ADVERTISEMENT - CONTINUE READING BELOWCONTINUE READING BELOWRecommended Videos
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View More Stories About
- baby’s development
- liver secreting bile
- pancreas producing insulin
- vocal cords
- baby teeth
- amniotic fluid
- painless contractions
- bones hardening
- joints jerking
- facial muscles
- vernix caseosa
- body temperature
- sleeping patterns
- bone marrow
- blood vessels
- air sacs
- neural connections
- immune system
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