There is one message every young woman needs to hear: The most significant factor affecting female fertility is age, and particularly the age of her eggs.
Our lives have changed dramatically in recent decades. Women spend more years studying, building careers and traveling, and sometimes find partners and start families later in life. The social clock has shifted, but the biological clock has not necessarily kept pace.
Pregnancy after 45
(Photo: Shutterstock)
The media also contributes to the perception that modern medicine allows women to postpone the decision to become pregnant, regularly highlighting celebrities who give birth at 45 or older. What those stories do not always tell us, however, is that some of these pregnancies are achieved using eggs frozen at a younger age or through egg donation.
It is important to understand that the age of the uterus is not the same as the age of the egg. Under suitable conditions and with appropriate hormonal treatment, an embryo created from a younger woman's egg can be transferred into the uterus of an older woman, which may be capable of carrying the pregnancy. But when it comes to producing a chromosomally normal embryo, the age of the egg is enormously significant.
Women are born with a finite supply of eggs, which does not increase over time. Quite the opposite: The number of eggs gradually declines. As a woman gets older, her chance of becoming pregnant in any given month decreases, her risk of miscarriage increases and the likelihood of producing a chromosomally normal embryo falls. This decline becomes more significant after age 35 and accelerates in the years that follow.
So what can women do?
Egg freezing for fertility preservation: If you are not planning to become pregnant in the near future, it is possible to retrieve and freeze eggs at a younger age for future use. Biologically, the eggs remain the age they were when they were frozen.
In Israel, women can undergo egg freezing for nonmedical reasons starting at age 30, allowing them to make an informed decision at a time when they still have more options.
However, it is important to emphasize that egg freezing does not guarantee the birth of a baby. Not every frozen egg will survive thawing, not every egg will be fertilized, not every fertilized egg will develop into a viable embryo, and not every embryo will implant successfully.
Which is better: Freezing eggs or embryos?
Some women choose to freeze embryos rather than eggs, while others combine the two options.
Embryo freezing has an advantage because it provides information about which eggs have been successfully fertilized and developed into embryos. However, this option requires sperm from a partner or donor and carries personal considerations, including whether to wait for a partner before making the decision.
Ultimately, egg freezing does not stop time, but it can provide women with peace of mind in an era when the new social clock is no longer synchronized with the biological one.
Dr. Ronit Almog is a specialist in gynecology, obstetrics and fertility treatment at Tel Aviv Sourasky Medical Center.