A ticking biological clock is the primary reason women choose to freeze their eggs. A woman's fertility peaks during her 20s and starts to decline once she reaches 30. In fact, by the time a healthy woman reaches age 30, her chances of conceiving start to see a decline coupled with other fertility-related issues as well.

source https://www.indiatvnews.com/lifestyle/news-bursting-myths-about-egg-freezing-here-s-what-you-should-know-672006