In vitro fertilization (IVF) has become an increasingly popular method for couples struggling with infertility to conceive a child.

The process involves the extraction of eggs from the woman’s ovaries, which are then fertilized with sperm in a laboratory. The resulting embryos are typically transferred into the woman’s uterus immediately following fertilization, but advancements in technology have allowed for the option of freezing these embryos for use in a later cycle.

This article explores the topic of whether freezing embryos has any impact on the success rates of IVF.

What is Embryo Freezing?

Embryo freezing, also known as cryopreservation, is a technique used to preserve embryos by cooling them to very low temperatures (-196°C) and storing them in liquid nitrogen.

This process allows for the preservation of embryos for extended periods of time, which can be useful for couples who are not ready to proceed with embryo transfer at the time of fertilization.

The Debate on Success Rates

Some researchers and experts have hypothesized that freezing embryos might decrease the success rates of IVF.

They argue that the freezing and thawing process could potentially damage the embryos, leading to lower pregnancy rates or higher rates of miscarriage. However, recent studies have shown that there is no significant difference in the success rates between fresh and frozen embryo transfers.

Research Supporting Frozen Embryo Transfer

A study published in the New England Journal of Medicine in 2018 compared the outcomes of IVF cycles using fresh embryos versus frozen embryos in over 2,000 patients.

The study found that the live birth rate per transfer was similar in both groups, with no statistically significant difference. This suggests that freezing embryos does not impact the chances of achieving a successful pregnancy.

Advantages of Freezing Embryos

Freezing embryos offers several advantages for couples undergoing IVF. One of the main benefits is the ability to have multiple attempts at pregnancy from a single cycle of egg retrieval, as frozen embryos can be stored and used in subsequent cycles.

This can save couples time and money by avoiding the need for additional egg retrieval procedures.

Another advantage is the ability to perform preimplantation genetic testing (PGT) on frozen embryos. PGT allows for the screening of embryos for genetic abnormalities before transfer, reducing the risk of implanting embryos with chromosomal disorders.

This can increase the likelihood of a successful pregnancy and decrease the chances of experiencing a miscarriage.

Disadvantages to Consider

While the success rates of frozen embryo transfers are comparable to those of fresh transfers, there are some disadvantages to consider.

The process of freezing and thawing embryos can be complex and may involve additional costs, such as storage fees for the frozen embryos. Additionally, not all embryos survive the freezing and thawing process, which can limit the number of embryos available for transfer.

Additional Factors Affecting IVF Success

It’s important to note that the success rates of IVF can be influenced by a variety of factors beyond whether the embryos are fresh or frozen.

The age of the woman, the quality of the embryos, and the expertise of the fertility clinic can all play a role in determining the likelihood of a successful pregnancy.

Additionally, some studies have shown that for certain patient populations, such as women with polycystic ovary syndrome (PCOS) or those undergoing elective single embryo transfer (eSET), frozen embryo transfers may actually result in higher success rates compared to fresh transfers.

Conclusion

The evidence suggests that freezing embryos does not reduce the success rates of IVF. Couples undergoing IVF can choose to freeze their embryos without worrying about compromising their chances of achieving a successful pregnancy.

The option of embryo freezing offers flexibility, increased chances for conception, and the opportunity to perform genetic testing. Ultimately, it is important for couples to consult with their healthcare providers to determine the most appropriate course of action based on their individual circumstances.