At 11 weeks, a fetus is undergoing rapid development and is finally starting to look like a little person. When parents-to-be see an 11-week-old baby via ultrasound, they often find themselves pleasantly astounded to be able to make out actual features of their little one, such as limbs and other body parts. Most vital organs have formed now, but they aren't completely finished their growth and development quite yet.
Size and Shape
An 11-week fetus is about 1 1/2 to 2 inches long and has the basic shape of a small human, as opposed to earlier weeks when he resembled something more akin to a tadpole. The proportions are much different than an adult human's however, with a head that is about the same size as the body and bulges out in the front. The weight of an 11-week fetus is approximately 1/3 of an ounce.
Skin and Eyes
The skin of a fetus at 11 weeks is transparent. Blood vessels are visible through the thin skin. At this time, the baby's eyes are fused shut. These eyelids are translucent and thin, just like the rest of his skin. The eyes themselves are slowly moving into position on the front of the baby's face, a change from the sideways position where they started forming.
Hands and feet are fully developed by 11 weeks, and tiny fingers and toes have separated and are no longer webbed. They are also beginning to develop fingernails and toenails. The baby's limbs are still curled inward, however, and will not begin to straighten for a few weeks. However, all of his joints are now working, so he can start exhibiting movement.
Internal Organs Outside
The intestines, in their rapid growth over the last few weeks, have bulged out of the abdominal cavity and into the umbilical cord. They have almost finished retreating back into the abdomen by 11 weeks, a process that will be completed before week 12 begins.
Activity is a big part of what you might see if looking at an 11-week fetus on ultrasound. Babies of this age are active swimmers in the amniotic fluid. Little legs and arms stretch and flex frequently as the baby starts to use his limbs.