Baby’s Development

Before 12 Weeks

Heart begins to beat by the 25th day.

Up to 1
Inch Long
Less than 1
Oz.

Changes to expect:

8-12 Weeks

Facial features are forming, and it’s a critical time for forming eye and ear structures. 

1
Inches
.5 to 1
Oz.

Changes to expect:

13-16 Weeks

Ears, arms, hands, fingers, legs, feet and toes form this month.

1
Inches
4
Oz.

Changes to expect:

17-20 Weeks

Baby begins a growth spurt. Hair appears on his or her head and kidneys begin to make urine.

5
Inches
0.75
Lbs.

Changes to expect:

You will really begin to feel the baby’s movements this month. Make a note of baby’s first movements if they have not already occurred.

21-24 Weeks

Baby’s skin is red, wrinkled and protected from the amniotic fluid by a white, cheesy coating called vernix.

5
Inches
1.5
Lbs.

Changes to expect:

Fetal movement increases.

25-28 Weeks

Fingerprints are forming. Eye lids open and close.

10
Inches
2.5
Lbs.

Changes to expect:

29-32 Weeks

Fine soft hair called lanugo covers the baby. The brain and nervous system are growing rapidly.

10
Inches
2.5
Lbs.

Changes to expect:

33-36 Weeks

Baby’s eyes are open. Skin is smooth because fat is being deposited.

12
Inches
5.5
Lbs.

Changes to expect:

37-39 Weeks

Baby’s eyes are open. Skin is smooth because fat is being deposited.

15
Inches
6.5 to 6.5
Lbs.

Changes to expect:

Fetal movement may seem decreased because there is less space to move around in the uterus.

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