Egg freezing technology gives women improved reproductive autonomy, the study shows

The largest U.S. report on elective fertility results so far found that 70 percent of women who froze eggs when they were under 38 - and later thawed at least 20 eggs - had a baby.

Led by experts from Grossman Medical School and the Langone Fertility Center NIU, the new finding is based on 15 years of actual thawing results of frozen eggs for women who have postponed childbirth and faced a natural decline in fertility over the years.

Published online May 18 at Fertility and sterility, the study also found that a significant number of women surveyed had more than one child through egg storage. In total, the study reported 211 babies from freezing eggs.

By comparison, with the use of fresh eggs or embryos from women trying to conceive, at the age of 40, less than 30 percent who received in vitro fertilization (IVF) became pregnant, and less than 20 percent gave birth to live babies as a result, according to collected statistics. Centers for Disease Control and Prevention (CDC) from nearly 500 fertility clinics in the country. Freezing and thawing eggs later provides a higher success rate in pregnancy than using fresh embryos during assisted reproductive technology, the study authors say.

Our findings shed light on the factors that accompany successful births from egg freezing, which include careful screening of embryos that are thawed and implanted. A better understanding of the live birth rate than egg freezing due to age-related fertility declines is necessary to inform patients’ decision-making. “

Sarah Druckenmiller Cascante, MD, lead author of the study, Associate in the Department of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, NIU Langone

“It is important that our study is based on real clinical experience,” adds Dr. Cascante, “instead of mathematical modeling with limited data, which is most of what has been published so far about the chance of being born from egg freezing.” older children have been increasing for three decades, with evidence that the trend will continue. The birth rate dropped for women in their 20s and jumped for women in their late 30s and early 40s, according to the U.S. Census Bureau. The average age at first birth increased from 19 in 1984 to 30 in 2021 and is higher in many urban areas.

Specialists within the Fertility Center were pioneers in the development of egg freezing technology, with the first baby born to freeze egg cells at NIU Langone in July 2005. The center has almost tripled the number of women who started the egg-freezing cycle in 2022 compared to 2019. As this national trend increases, more data is needed to inform patients who want to secure their reproductive future.

Study details

The study involved 543 patients with an average age of 38 years at the time of the first egg freezing, which is older than the optimal age for freezing eggs (35 years or younger). These patients had 800 egg-freezing cycles, 605 egg-thawing cycles, and 436 embryo transfers between 2005 and 2020.

The investigation found that, in total, 39 percent of women between the ages of 27 and 44, with most between the ages of 35 and 40 at the time of egg freezing, had at least 1 child from their frozen eggs, comparable to IVF outcomes. age-appropriate. . At all ages, women who thawed more than 20 mature eggs had a live birth rate of 58 percent, which was profound and unexpected because this group included people who had passed the reproductive years. In fact, 14 patients who froze eggs between the ages of 41 and 43 successfully obtained children from their frozen eggs. As noted, women under the age of 38 who had 20 or more mature eggs achieved a live birth rate of 70 percent per patient. The length of storage of frozen eggs did not change the success rate.

The results also showed that genetic screening before implantation with embryos from frozen and eventually thawed eggs resulted in lower abortion rates and higher live birth rates per transfer. Such screening also enables the transfer of individual embryos, which leads to a single pregnancy, which is safer for both mother and child, the authors say.

“Our results provide realistic expectations for those thinking about preserving eggs and show that egg freezing technology gives women improved reproductive autonomy,” says senior study author James A. Grifo, MD, PhD, Director of the Department of Reproductive Endocrinology and Infertility and Fertility Center. “Freezing eggs in your youth becomes an option to be your own egg donor in your advanced years. As younger patients freeze eggs and work more than one cycle, success rates will be even higher than reported in this study. “

Dr. Grifo, also a professor in the Department of Obstetrics and Gynecology, warns that the study is limited by the number of patients. Future larger studies are underway to increase the set of data that patients can benefit from and model expected success rates. He adds that additional studies from various geographical locations and types of centers are necessary.

Support for funding basic scientific studies that led to a clinically successful program of egg freezing and embryo banking at NIU Langone was provided by the Carolin and Malcom Wiener Foundation.

In addition to Dr. Cascante and Dr. Grifo, other clinical scientists in the study were Jennifer K. Blakemore, MD; Shannon M. DeVore, MD; Brooke Hodes-Vertz, MD, MPH; Elizabeth Fino, MD; Alan S. Berkeley, MD; Carlos M. Parra, MD; and Dr. Caroline McCaffrey. The entire team of embryologists, physicians, nurses, and support staff at NIU Langone Fertility Center contributed to the success presented in this study.