[Xylochick216]

From what I know, couples using IVF get many eggs during the egg retrieval and try to fertilize as many as possible to increase their chances that at least 2 will fertilize. The best two (or one or three) are then used in IVF. Couples must sign forms prior to starting the process to decide what to do with the leftover embryos. Couples can store them to use in the future (sparing the entire IVF process next time), donate them, or destroy them.