The amniotic fluid that has cushioned and supported the baby in the uterus now serves another purpose. The intestines have developed enough that small amounts of sugars can be absorbed from the fluid the baby swallows and will be passed through the digestive system to the large bowel. Almost all of the baby's nourishment, however, still comes from Wendy through the placenta.
Until now the baby's liver and spleen have been responsible for the production of blood cells. (The fetal liver stops producing blood cells a few weeks before birth and the spleen stops by week 30.) But now the bone marrow spaces are developed enough to contribute to blood cell formation as well, and bone marrow will become the major site of blood cell production in the third trimester.
