Egg freezing techniques empower women by improving reproductive autonomy, studies show

According to the largest report in the United States on the results of selective fertility preservation so far, 70% of women who frozen eggs when they were under 38 years old and later thawed at least 20 eggs had babies.

New discoveries, led by experts at the NYU Grossman School of Medicine and the NYU Langone Fertility Center, were based on the results of 15 years of actual frozen egg thawing in women who delayed childbirth and faced a natural age-related decline in fertility.

Published online on May 18th Fertility and infertilityThe study also found that a significant number of the women studied had multiple children through egg storage. In total, this study reports 211 babies from egg freezing.

By comparison, using fresh eggs and embryos from women who are about to become pregnant, less than 30% of babies undergoing in vitro fertilization (IVF) at age 40 become pregnant and, as a result, less than 20% are alive babies. I gave birth. According to the Centers for Disease Control and Prevention (CDC) from about 500 fertilization clinics nationwide. Freezing and thawing eggs at a later date has a higher pregnancy success rate than using fresh embryos during assisted reproductive technology, according to the authors of the study.

Our findings shed light on factors that track successful births from egg freezing, including careful screening of embryos to be thawed and transplanted. To inform patient decision-making, we need a better understanding of the fertility rate of egg freezing due to age-related fertility decline. “

Sarah Drakkenmirer Cacante, MD, Principal Writer, Fellow of NYU Langone Obstetrics and Gynecology Endocrinology of Reproductive Endocrinology and Infertility

“Importantly, our study is based on real-world clinical experience, not mathematical modeling with limited data, which is most of what has been published so far about the potential for childbirth due to egg freezing.” Adds Dr. Cascante. The number of women in the United States with older children has increased for 30 years, indicating that this trend will continue. According to the US Census Bureau, the fertility rate of women in their twenties has declined, and the fertility rate of women in their late thirties and early forties has skyrocketed. The average age of first birth increased from 19 in 1984 to 30 in 2021, which is higher in many metropolitan areas.

Fertility Center experts are pioneers in the development of egg freezing technology and have the first baby born by egg freezing in NYU Langone in July 2005. The center needs more data to inform patients seeking a future of reproduction as the number of women who started the egg freezing cycle in 2022 is 2019. Will be.

Details of the study

In this study, 543 patients participated with an average age of 38 years when the first eggs were frozen. This is older than the optimal age for freezing eggs (35 years or younger). These patients underwent 800 egg freezing cycles, 605 egg thawing, and 436 embryo transfers between 2005 and 2020.

Overall, 39% of women aged 27-44 years accounted for the majority of 35-40 years of age when the eggs were frozen, and the survey found that frozen eggs gave birth to at least one child. This is comparable to age-matched IVF results. .. At all ages, the fertility rate for women who thawed 20 or more mature eggs was 58%. This was profound and unexpected, as this group included people who exceeded the reproductive prime. In fact, 14 patients who frozen eggs between the ages of 41 and 43 succeeded in giving birth to frozen eggs. As mentioned earlier, women under the age of 38 who thawed 20 or more mature eggs achieved a fertility rate of 70% per patient. There was no change in the success rate for the storage period of frozen eggs.

The results also showed that pre-implantation gene screening with embryos from frozen and finally thawed eggs reduced miscarriage rates and increased fertility per transplant. Such screening also allows for a single embryo transfer, resulting in a single pregnancy that is safer for both mother and offspring, the authors say.

“Our results provide realistic expectations for those considering oocyte conservation and show that egg freezing techniques improve female reproductive autonomy,” said a senior researcher. The author, James A. Grifo, Ph.D. of Medicine, Director of Reproductive Endocrinology and Infertility and Fertility, said. center. “Freezing eggs at a young age is an option for becoming an egg donor at an older age. Younger patients freeze their eggs and perform multiple cycles, so success rates are reported in this study. It will be even higher than it is. “

Dr. Grifo, a professor of obstetrics and gynecology, warns that research is limited by the number of patients. Larger future studies are underway to increase the data sets that patients can benefit from and model the expected success rate. He adds that additional research from various geographic locations and center types is also needed.

Funding for the underlying scientific research that led to NYU Langone’s clinically successful egg freezing and embryo banking program was provided by the Carolyn and Malcom Wiener Foundation.

In addition to Dr. Cascante and Dr. Grifo, the other clinician-scientist in this study was Jennifer K. Blakemore, MD. Shannon M. DeVore, MD; Brooke Hodes-Wertz, MD, MPH; Elizabeth Fino, MD; Alan S. Berkeley, MD; Carlos M. Para, MD; Dr. Caroline McCaffrey. The entire team of embryologists, doctors, nurses, and support staff at the NYU Langone Fertility Center contributed to the success presented in this study.