Substitute for freezing embryos?

A California woman recently gave birth to a son conceived using both an egg and sperm that had been frozen. She was part of a study aimed at improving techniques for egg-freezing, which has proven much more difficult than successfully freezing sperm — according to the article, only about 200 children have been born from frozen eggs.

Egg-freezing is being promoted as a way for women to preserve their eggs so that they can become pregnant later in life. But I can think of another possible benefit. One reason “excess” embryos get created and frozen is that egg harvesting is both hard on the mother and expensive, so couples want to maximize their chances of conception for each harvest. If freezing of eggs can be made to work reliably, then women could be spared multiple egg harvests while still creating only as many embryos as they intend to implant in any given cycle.