Your baby today
Fetal development begins the moment the egg is fertilized. This week your baby is the size of a poppy seed, and while this may seem small, your baby is already 10,000 times larger than they were at conception!
By four weeks of pregnancy, your baby’s development has rocketed! All of their major organs have begun to develop, and they now have arm and leg buds. In addition, your baby is no longer receiving nutrients from the yolk sac but is instead receiving their nutrients and oxygen via the placenta and umbilical cord.
The first four weeks are also when the baby’s nervous system begins to develop along with their brain and eyes. Most doctors recommend pregnant women or women trying to become pregnant take folic acid and other prenatal vitamins or supplements in preparation for their developing baby. Folic acid is known to prevent congenital disabilities, especially those related to the brain, neural tube, and spine.
You may still be confused about whether or not you're pregnant, or you may want to find out more about early pregnancy signs, symptoms and your baby's size (no bigger than a poppy seed!
This content has been adapted and updated by L. Elizabeth Forry from its original text: Pregnancy Day by Day by Consultant Editor, Paula Amato, MD (Copyright © 2008 Dorling Kindersley Limited).