Trimester Two – Weeks 13 through 20

Many women look forward to the second trimester.  Many unpleasant first trimester symptoms subside, and women can resume most of their normal activities.  The fetus's rapid development and the growing bump may make the pregnancy seem more real, and risk of miscarriage is greatly reduced.

Second Trimester Fetal Development

Weeks 13

The fetus has fully-functioning nerves, organs, and muscles, and it flexes and kicks considerably.

Week 14

The fetus's hormone production increases and sex organs develop.

Week 15

Skin begins to form.  Bone and marrow that will comprise the skeleton continue to form.

Week 16

Fetuses are able to make facial expressions, hiccup, and make a fist.  Female fetuses are forming millions of eggs in the ovaries.

Week 17

Fat stores that will protect the organs after birth begin to develop under the skin.

Week 18

The fetus is able to hear and swallow.

Week 19

The fetus can now make reflexive muscle movements.  A fine layer of hair called lanugo, and a pasty white coating called vernix, cover the skin.

Week 20

The skin thickens, and the limbs are well-developed.  The fetus weighs a little over half a pound and is about six inches long.

Second Trimester Pregnancy Signs

As symptoms of early pregnancy subside in the beginning of the second trimester, many women experience an increase in their energy level and appetite.  Women also begin to "look pregnant" at this point.  Many women enjoy a rosy glow, since their circulatory systems expand to increase blood flow to the fetus.  Other skin changes, including varicose veins, stretch marks, and brownish marks on the face or abdomen, will generally fade in the months after giving birth.  Women should be sure to get regular, moderate exercise to improve circulation and prevent swelling and unnecessary weight gain. 

Continued Reading:

Trimester Two - The Second Half