By week 10 of the pregnancy, all of your baby's vital organs have begun to form. The embryonic tail has disappeared completely, and baby’s fingers and toes are fully separated. The bones of the skeleton are now forming. Your baby's eyelids are more developed, and the eyes look closed. The outer ears are starting to assume their final form. Your baby is also starting to develop buds for teeth. His or her brain is now growing more quickly. In week 10 almost 250,000 new neurons are being produced every minute. If your baby is a boy his testes will start producing the male hormone testosterone.
There is an increase in the amount of blood that is circulating in your body, which may cause you to feel warmer than usual. Your uterus is now the size of a large orange and your changing shape may mean that you are more comfortable in loose-fitting clothes that do not restrict you. Other changes are also taking place in your body. Although these are not always physically obvious, they are in fact the result of shifts in your body’s chemistry.
The external ears are now visible on the head, which is growing fast to make room for the brain. The fetal body is elongating and its fingers and toes are clearly defined but are still joined with webs of skin. At week 10 of your pregnancy the fetus is now about 1.22 inch (3,1 cm) long from crown to rump and weighs around 0.14 ounce (4 gram).