70% of women who stored eggs when they were younger than 38 and thawed at least 20 eggs later produced a baby, according to the biggest U.S. report on elective fertility preservation outcomes to date.
The new discovery was based on 15 years of “real life” frozen egg thaw outcomes for women who had delayed childbearing and experienced natural, age-related fertility decrease, according to specialists at NYU Grossman School of Medicine and the NYU Langone Fertility Center.
The study, which was published online in Fertility and Sterility, also discovered that a significant majority of the women analysed had more than one child as a result of egg preservation. In total, 211 kids were born as a result of egg freezing, according to the study.
According to statistics gathered by the Centers for Disease Control and Prevention from the nation’s nearly 500 fertility clinics, fewer than 30% of women undergoing in vitro fertilisation (IVF) at age 40 became pregnant, and fewer than 20% gave birth to live babies as a result of using fresh eggs or embryos from women trying to conceive. According to the study authors, egg freezing and thawing at a later period has a greater pregnancy success rate than using fresh embryos through assisted reproductive technology. NYU Langone Fertility Center specialists were pioneers in the development of egg freezing technique, with the first baby born by egg freezing at NYU Langone in July 2005.
In compared to 2019, the number of women initiating egg freezing cycles has nearly tripled in 2022, according to the Center. More data is needed to inform patients who want to guarantee their reproductive futures as this national trend grows. 543 patients took part in the trial, with an average age of 38 at the time of the first egg freeze, which is older than the recommended age for freezing eggs (35 years old or younger). Between 2005 and 2020, these patients had 800 egg freezing cycles, 605 egg thaws, and 436 embryo transfers.
Overall, 39 percent of women aged 27 to 44, with the majority aged 35 to 40 at the time of egg freezing, had at least one child from their frozen eggs, which is comparable to age-matched IVF outcomes. Women who froze more than 20 mature eggs had a 58 percent live birth rate across all ages, which was significant and surprising given that this group comprised patients well past reproductive prime. In fact, 14 patients between the ages of 41 and 43 who froze their eggs successfully had children from their frozen eggs. As previously stated, women under the age of 38 who had 20 or more mature eggs thawed had a 70% live birth rate per patient.
The success rate was unaffected by the time of frozen egg storage. Preimplantation genetic screening of embryos from frozen and later thawed eggs also resulted in decreased miscarriage rates and greater live birth rates per transfer, according to the findings. According to the scientists, such screening allows for single embryo transfers, resulting in singleton pregnancies that are safer for both mother and child.
The study was limited by the number of patients, according to the researchers. Larger studies are being planned in the future to expand the data set from which patients can benefit and model their projected success rates.