Understanding Egg Freezing: A Closer Look

Contrary to popular belief, the effectiveness of egg freezing is often underappreciated. Major publications like The New York Times and Vox have reported that only about 40% of women will successfully conceive using frozen eggs. Additionally, articles criticizing companies for offering egg freezing as a benefit present an overly pessimistic view. Terms like “the odds are stacked against you” from Glamour and statements noting low success rates from sources like the Financial Times and Business Insider add to this narrative.

The studies these articles often cite, particularly one from 2022, indicate only 39% of patients had a child, but they overlook that the typical age of women freezing their eggs was 38. By this point, their fertility was already significantly decreasing. Importantly, the decline in fertility is mostly linked to egg quality rather than the age of the womb. Hence, women freezing their eggs in their twenties might have similar chances of successful IVF later on. In fact, the oldest recorded woman to give birth with a young donor egg was 74 years old.

This kind of negative media coverage can have real-world implications. Many women, including those who undergo the egg freezing process themselves, are unaware of its potential success rates. Even medical students and doctors seem to lack the necessary information.

Instead of freezing their eggs when it’s most beneficial—in their twenties—many women treat it as a last resort. Interestingly, the rate of egg freezing among younger women (ages 18–34) matches that of women aged 43–44, despite the significant drop in the success of using one’s own eggs at that age (less than 10%) compared to around 85% for those under 35.

Ultimately, the decision to freeze eggs is a personal one, influenced by finances, life circumstances, relationship status, and career aspirations. It’s not a guaranteed success; some women experience infertility or bad luck. However, it does offer many women a viable option, especially when done earlier than later.

As women in our late twenties, we are taking steps to freeze our eggs, ensuring we can have the desired number of children regardless of future changes in our lives or careers. One of us is involved in biology (Ruxandra) while the other has a background in economics (Luzia). Together, we aim to clarify this emotionally charged process and encourage more young women to consider it.

Age and Fertility

So, why does fertility decline with age? Conventional wisdom holds that it remains stable until a sharp drop after 35. However, measuring this accurately is difficult, as many studies use small or non-representative samples. Recent research suggests a more nuanced picture.

The misunderstanding lies in the distinction between fertility and fecundability. Fertility refers to the total number of births per woman over time, while fecundability is the monthly chance that a woman will conceive with regular unprotected intercourse. The two terms reflect different aspects of reproductive capability.

Notably, many of the historical studies relied upon to form these views included populations where younger women were often biologically incapable of conceiving, thus skewing the data. In reality, when focusing on women who can conceive, evidence indicates that fecundity gradually declines from the early twenties onward without an abrupt change in the mid-thirties. This decline stems from both a reduction in the quantity and quality of eggs.

The Depletion of Ovarian Reserve

Women are born with all the eggs they’ll ever have, typically ranging from two to six million. Most remain immature, with only a few preparing for ovulation each month. Over time, this pool shrinks significantly; by menopause, only about a thousand may remain. This natural decline ties closely to the antral follicle count, explaining decreasing IVF success rates as age increases.

Egg Quality Deterioration

The quality of eggs also wanes with age, affecting their chromosomal stability. Unlike most body cells—constantly renewing themselves—eggs remain dormant for years. This prolonged inactivity doesn’t prevent the detrimental effects of aging, leading to damaged proteins and chromosomal issues.

As the biological mechanisms that hold chromosomes together weaken, mismatches during cell division become more common, resulting in eggs with abnormal chromosome counts. Such issues often lead to unsuccessful pregnancies, with some abnormalities associated with higher maternal ages becoming prevalent.

Navigating Egg Freezing and IVF

The IVF process involves several evaluations, including hormone tests and ultrasounds for assessing the number of antral follicles. Once ready, a regimen initiates egg maturation over 10–12 days. Many follicles yield eggs, which then undergo fertilization and further development. However, attrition is common; only a fraction will complete development and be suitable for transfer.

Egg or embryo freezing processes follow similar procedures but each culminates in retrieving eggs or forming embryos for preservation. Modern techniques, like rapid flash freezing, have vastly improved survival rates compared to earlier slow freezing methods.

Expectations and Costs

On average, women aged 18–34 undergoing embryo freezing cycles can expect around 14 eggs per cycle, though there’s a wide range. Young women often fare even better; a significant study highlighted those under 35 achieving even higher egg retrieval rates.

Many women perceive egg freezing as prohibitively expensive due to U.S. and UK costs, but options exist elsewhere, such as Spain, where similar treatments are notably more affordable. Additionally, many clinics offer local monitoring, reducing travel needs.

The quality of clinics varies widely, influencing success rates. Major factors like oxygen levels in embryo cultures may affect outcomes significantly. Research indicates stark contrasts between top-performing clinics and others with much lower success rates, underscoring the importance of verifying clinic performance.

Considering Egg Freezing?

The real issue surrounding egg freezing today is not effectiveness but clarity. If you’re a woman in your twenties or early thirties with plans to one day have children, egg freezing could be a worthwhile option, particularly if financially feasible. Those uninterested in children may not see the need.

For a reasonable chance of future pregnancies, aiming to freeze about 20 eggs is advisable at the right age. While studies present varying numbers, general estimates suggest freezing around this amount could maximize success rates. Remember, the best time to conceive remains when someone is young, and egg freezing can provide flexibility without relinquishing that possibility.