The baby should be 2.5 inches long and weigh approximately 0.3 to 0.5 ounces.
Fetal developments that usually occur during week 12 include the following:
- A skeleton of cartilage is forming
- The gallbladder secretes bile from the fetus
- The lungs are completely formed
- The thyroid gland and pancreas are now complete
- The liver is functioning to make blood cells
- The liver accounts for about 10 percent of the entire weight of the fetus
- The baby's first urine is made and eliminated into the amniotic sac
- The baby's intestines can now fit into his/her abdomen instead of stretching into the umbilical cord.