Egg freezing, or mature oocyte cryopreservation, is a method for women to preserve reproductive potential by harvesting and freezing unfertilized eggs for later use. This process is often pursued by women with diminished ovarian reserve or those considering delayed childbearing, particularly if they are in their late 30s or want multiple children. While it offers a chance to conceive later, egg freezing is not guaranteed success and is recommended primarily for women in their 20s to early 30s.