I am very interested in in vitro fertilization, but I want to be informed on every issue before going ahead with the procedure. I am concerned about the "nutrients" that sustain the egg in the dish. What exactly is used as these nutrients? I read that sometimes blood serum is used. Is this true in all cases? Are any other nutrients used besides blood serum?

-- Jess

There are many types of nutrient media to support embryo growth. As research on in vitro fertilization (IVF) proceeds very slowly, we are only starting to learn which components are necessary to provide the best environment for the embryo. Protein is one ingredient needed to support embryo growth. Some programs use blood serum from the mother for the protein source, while others use a bovine (cow) source of protein or a synthetic protein substitute.

Each component in the growth media can interfere with the action of another component. When studies show that one component of the media needs to be changed, we need to reevaluate all other components. So careful consideration is given before any changes are made.