By Emily Merrell
At what point on a woman’s fertility journey should one explore egg freezing? It’s become a more popular benefit for companies to offer their employees and is known as a way to broaden our range of choices later in life – but what are the steps? Dr. Jennifer Blakemore, an Assistant Professor in the Department of Obstetrics and Gynecology at NYU Langone Fertility Center, is answering all our questions about the egg freezing process. An expert in the field, she’s actively involved in research, and has published numerous articles in Fertility & Sterility, Human Reproduction, and the Journal of Assisted Reproduction and Genetics.
SDS: What is egg freezing and how does it differ from IUI, IVF and embryo freezing?
DR. JENNIFER BLAKEMORE: A great question! And one that I think is best started with a small review of physiology. All people with ovaries are born with all the eggs they will ever have (we don’t make new ones). Each month during the course of a natural menstrual cycle, the ovary releases a small cohort of eggs (roughly 15-20 on average) that your body can use. Your brain then produces hormones that stimulate one of your ovaries to release a single mature egg from that cohort and the others disappear. We utilize this physiology by giving hormones, known as fertility medications. These medications stimulate the ovaries to mature several eggs from the cohort at once, instead of just one.
The process begins the same for egg freezing, embryo freezing and IVF cycles. We give fertility medications to stimulate multiple mature eggs in one month and then retrieve them in a short, minor surgical procedure to bring the eggs into the laboratory. What differentiates the three procedures is what happens once mature eggs are retrieved. In an egg freezing cycle, mature eggs are frozen and stored for future use. In an embryo freezing cycle, mature eggs are combined with sperm to create embryos, which are frozen for future use after 3-5 days of development. In an IVF (in vitro fertilization) cycle, embryos that have reached the blastocyst stage of development are transferred back into the uterus to achieve pregnancy.
Lastly, IUI (Intrauterine Insemination) does not involve retrieving eggs from the body. Instead, IUI enables conception by directing sperm to the right place at the right time. A thin catheter is placed directly into the cervix, and a carefully prepared sperm sample is placed directly through the catheter into the uterus to be as close as possible to the egg that is about to be released from the ovary. IUI increases the chances of becoming pregnant by getting optimal sperm directly into the uterus at a time when the woman is most fertile.
Egg freezing and embryo freezing are great options for patients considering having children in the future, while IUI and IVF are for patients actively trying to conceive.
SDS: At what point on a woman’s fertility journey should one explore egg freezing? Is there an optimal age?
DJB: Egg freezing is a great option for anyone with ovaries who is in their 20’s, 30’s, or early 40’s – regardless of race, marital status, or sexual preference – who wants a child at some point in the future. At birth, the ovaries contain ~2 million eggs (!) but the quality and quantity of these eggs (known as Ovarian Reserve) decrease naturally over time. Beginning around age 30, a woman’s fertility begins to decline with the rate of decline accelerating after age 35. However, the rate at which fertility declines is different for every individual. A comprehensive fertility health screening is a great way to learn more about your reproductive system and determine if egg freezing is right for you!
SDS: How long do eggs last for?
DJB: Eggs can be safely kept frozen for as long as you need them. There is no current evidence to suggest that they deteriorate with time, so you can take as long as you need to prepare for your future family. If/when you decide to start your family using your previously frozen eggs, eggs are thawed and combined with sperm to create embryos. We check the embryos for health and viability, and then choose the best one for Single Embryo Transfer. Patients who do not use their frozen eggs may choose to have the eggs discarded or may elect to donate their eggs to scientific research.
SDS: Are there a certain number of eggs selected that make egg freezing successful?
DJB: There is no “right” number of eggs per egg freezing cycle. The number of eggs retrieved during egg retrieval depends on a number of factors, including age and ovarian reserve. While your doctor will have an idea of how many eggs you can expect based upon follicular growth during ovarian stimulation, we won’t know the exact number of eggs until after retrieval.
Before beginning your cycle, speak with your physician about your fertility goals. You and your doctor will then work together to develop your fertility preservation treatment plan and determine how many eggs you may need to build your future family, which is different for everyone!
SDS: Do you have any recommendations on egg freezing during COVID-19?
DJB: Despite what some originally thought, the COVID-19 pandemic has actually led to an increase in the number of patients choosing to freeze their eggs. At NYULFC, we’ve adapted to the pandemic by implementing several safety measures to keep you, your cycle and your eggs safe. These safety measures have proven very effective and we have even published our safety guidelines!
We urge patients to be cautious during their cycle to limit potential exposure to the virus as a positive test may cancel or suspend their cycle. Overall, if you are interested in egg freezing, talk to your physician – but we won’t let COVID-19 stop you from achieving your goals!
SDS: How can people find out more about egg freezing with NYU Langone?
DJB: To learn more about egg freezing at NYU Langone Fertility Center, visit our website https://www.fertilityny.org/ or find us on Instagram at https://www.instagram.com/fertility_ny/. We’re here to go at your pace and answer any questions you may have. Your future, your timeline. We’re ready when you’re ready!
