Pregnancy 6 Weeks
Fetal Development
Your period is now 1 week late. If you have irregular periods, or experienced implantation bleeding, you still may not realise you are pregnant!
Since it's very difficult to measure your baby from head to toe (he or she is shaped like the letter "C"), the "crown to rump length" is used instead during the first few months. The baby is measured from the crown of their head to the base of their rump. By the end of this week the baby will measure around 0.08 to 0.16 inches (Crown to Rump).
Your baby's heart is already beating at a regular rhythm. The heart is now just a long tube, but by week 10 it will have developed into it's various chambers and valves. You will have to wait until week 10-12 before you can actually hear your baby's heart. Blood circulation is well established, with the blood being produced by the yolk sac.
Your baby's neural tube, which connects the brain and spinal cord, now closes. Be sure to take the B vitamin, folic acid, during the first two months of pregnancy to reduce the risk of serious birth defects of the brain and spiral cord. More than 50% of neural tube defects can be prevented this way.
During this week, small hand and feet buds are beginning to appear. The umbilical cord, which provides nourishment and oxygen from the placenta to your baby, and removes carbon dioxide and waste products from your baby, develops from the implantation site of the blastocyst. The placenta will soon take over from the yolk sac.
The larynx (voice box) begins to form, as well as the inner ear and eyes. The beginnings of the digestive and respiratory systems are evident.
