Title: Pregnancy Guide, Stages of Pregnancy, Fetus Growth
Headings: Week-by-Week Pregnancy Guide
Week-by-Week Pregnancy Guide
Trimester One - Weeks One through 12
First Trimester Fetal Development
Trimester Two - Weeks 13 through 27
Second Trimester Fetal Development
Trimester Three - Weeks 28 through 40
Third Trimester Fetal Development
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Content: Changes to a woman's body, and development of the fetus, are considerable during this time. 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.