The Developing Baby: Week 9-12 Health Article

Weeks Nine through Twelve

The body begins to lengthen and growth of the head slows down. Bones are beginning to form. The liver and spleen are creating blood cells. The fetus begins to move, though, the mother will not feel this for several more weeks because the fetus is too small. The sex of the fetus is now distinguishable to the naked eye, although by ultrasound, this is still difficult to tell. Before this time, the sex of the fetus looks the same in both girls and boys. Finally, during the 9th and 12th weeks of pregnancy, the fetus' kidneys are starting to work, and fetal urine is excreted into the bag of water, creating amniotic fluid.

For more information, go to The Developing Baby: Week 1-2 and The Developing Baby: Week 3-8.