Cryopreservation is the preservation of frozen eggs, embryos, or sperm at freezing temperature for later use. 

The best time for a woman to think about freezing her eggs to use for a later pregnancy would be in her late 20s or early 30s because fertility begins to wane once a woman reaches a certain age. Women will often have a greater ovarian reserve (the number of eggs in their ovaries) and better-quality eggs at that time.

Cryopreservation is a sophisticated, generally safe method that frequently results in a successful pregnancy in the future. According to research, the freezing and thawing of embryos do no harm to the offspring that result from frozen embryos. It is thought to be just as safe as having children from “fresh” embryos.