Your Guide to Becoming a Mother | Fit Pregnancy

Your Guide to Becoming a Mother

Get your baby off to a safe start.


2 weeks

Size>>About 1 millimeter long (slightly larger than a pinhead)

Looks like>>A cluster of cells

What’s going on>>The blastocyst is attached to uterine lining and starting to sort itself out into different layers.

3 weeks

 Size>>Approximately 1.25 millimeters long (about the size of a small sesame seed) Looks like>>An even larger cluster of cells What’s going on>>Embryo’s heart, brain, spinal cord, muscles and skeleton are beginning to form.

4 weeks

Size>>2–4 millimeters long (about the size of a large sesame seed) Looks like>>A tadpole, complete with a head and tail What’s going on>>Brain and spinal cord develop; eyes and limbs begin to form; heart begins beating.

5 weeks

Size>>1/2 inch long (crown to rump; about the size of a raisin) Looks like>>A tadpole with thick arm and leg buds What’s going on>>Arms, legs, hands and feet continue to develop; heart divides into two chambers; air passages form in lungs; eyes are forming.

6 weeks

 Size>>1/2–3/4 inch long (approximately the size of a pinto bean) Looks like>>a tadpole with longer arms and legs; eyes, nose and ears begin to show What’s going on>>Fingers and toes develop; embryo starts to move.

 7 weeks

 Size>>1–11/2 inches long (about the size of an olive) Looks like>>Eyes, nose, mouth, fingers, toes and ears are clearly visible. What’s going on>>Head, neck, fingers, toes and outer ears developing; movement can be seen on ultrasound.

8 weeks

Size>>11/4–13/4 inches long; weighs about 5 grams (about 1/5 oz.); about the size of a walnut Looks like>>Resembles a baby more, with a large head and recognizable features. What’s going on>>Most organ systems growing quickly; reproductive tract yet to form.

9 weeks

Size>>1 1/2–2 1/2 inches long; about 8 grams (roughly the size of a large lime)

Looks like>>Head still

disproportionately large, but limbs are catching up.

What’s going on>>Head stretches upward from chest; neck lengthens; fingernails

and external genitals begin

to appear.

10 weeks

Size>>2 1/2 inches long;

about 8–14 grams (about the size of a small lemon)

Looks like>>Body size begins to catch up with head.

What’s going on>>Most

of the body is formed; hair starts to grow; genitals begin to look male or female; fetus can squint, open mouth, move fingers and toes.

11 weeks

Size>>2 1/2–3 inches long; weighs 13–20 grams (under 1 oz.; about the size of a tennis ball)

Looks like>>Face continues to look more humanlike; external genitals have distinct male or female form.


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