During the first trimester your baby will go through some amazing changes. The first trimester is the most important time for the fetus because of all the development going on. The most development occurs during the first trimester and then each trimester builds upon the first trimesters work.

Fetal development begins with the fertilization of the egg by the sperm. As soon as this occurs the fetus will begin its growth as a little boy or a little girl. Next, the fertilized egg makes its way to the uterus where it will implant. At this point the neural tube begins to form. This tube will eventually be the central nervous system and responsible for the brain, hair, skin, and spinal cord. The heart and circulatory system become rudimentary functioning during the first four weeks of pregnancy and continue to develop throughout the first trimester.

By the fifth week the heart should begin beating. The umbilical cord develops and the four chambers of the heart begin pumping blood about this same time. Arm and leg buds develop during this week and the lungs and brain begin developing as well. All of these will continue to develop and grow more over the rest of the pregnancy.

The nerves from the brain to the nose form and the nostrils are formed. The intestines grow and the pancreas begins working. The eyes are even developing this early on and as the lens develops.

Fingers begin developing and the elbows show up as well. Teeth start forming under the babys gums and the feet start developing more and toes begin to show up. The bones and cartilage begin forming during the eighth week and the tongue starts to develop as well.

By week nine the baby is moving around, has fingerprints, and would try to grasp your finger if you placed it in her hand. Almost all the joints are formed at this stage as well. By the tenth week all the major developmental hurdles will have been jumped and your little one will officially be called a fetus. And, although you cant see them, your babys eye color is already set at this early stage of pregnancy.

Week eleven sees the growth of hair and nails as well as the formation of the genitals. Almost all organs are formed and functioning at this point. By week 12 the pancreas is producing insulin, the liver is working, and vocal chords are formed. By week 13 you should be able to hear your babys heart by the Doppler machine at your doctors. And by week 14 the baby is almost fully developed with the tough job of growing left for the rest of the time en utero.

Posted in Pregnancy

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