Your little one is approximately 1/3 of an inch long by the end of the week, measuring from crown to rump. Not much bigger than an M & M candy (the kind without the peanut)! Your baby’s weight is less than a gram; oh so tiny! Your baby has a whole lot of growing to do before he or she reaches delivery weight, but the growth and development continues very rapidly during this embryonic period.
Your baby’s umbilical cord continues it’s development, which is vital for providing nourishment to your unborn baby. Along with the umbilical cord, facial characteristics are continuing their formation, with the beginnings of eyes including the lenses and pigmentation of the irises. The black pigmentation is visible under the skin covering your baby’s eyes. The eyes are still located more to the side of the head at this point in development.
Two holes are visible on your baby’s face, which will soon form into the nostrils of the nose. Your baby’s head is bent forward on his or her chest and the tiny brain inside is going through some rapid changes, with the brain as well as the spinal cord almost complete. Cavities and passages necessary for circulation of spinal fluid have formed.
Although your baby’s small heart is still bulging from his or her body right now, it has grown and developed two more chambers; for a grand total of four. It is pumping blood throughout your baby’s body and beating at approximately 150 beats a minute, which can easily be picked up by ultrasound by the end of this week. It would look like a tiny flicker on the monitor.