Did you know that women have a finite amount of time during which they can reproduce?
Unfortunately, the “biologic clock” concept is a real thing for women. Unlike men who continuously make sperm, women are only born with a set number of eggs. At the time of birth, female babies are born with approximately 1 million eggs and by the time puberty is reached they are left with approximately 300,000 eggs. This decline in the number of eggs continues during a woman’s life with an increase in the rate of decline starting at the age of 35 years old, and a much more rapid rate of decline for women who are over 40 years old. And with this increasing maternal age, the quality of the eggs also declines, which can make it harder to conceive and put one at a higher risk of having a genetically abnormal pregnancy or miscarriage.
Unfortunately, the “biologic clock” concept is a real thing for women. Unlike men who continuously make sperm, women are only born with a set number of eggs.
So, what can women do to take control of their family planning?
Oocyte cryopreservation (OC), or more commonly known as Egg Freezing, is an option that allows women to regain some control over their fertility. Oocyte cryopreservation refers to freezing of a woman’s eggs. This procedure has been around for decades. The first baby born as a result of OC was born in 1986. A technique called vitrification over the past 20 years has improved the technique for OC. Vitrification refers to a rapid cooling technique to freeze the oocytes. Ice crystal formation is minimized with vitrification compared to the older process of slow freeze, and hence oocyte survival during the thaw process has improved.
Oocyte cryopreservation initially was considered “experimental” and limited to women who might be facing losing their fertility due to iatrogenic causes such as the gonadotoxic treatment of some chemotherapy regimens for cancer. Other medically necessary reasons for Oocyte cryopreservation also included freezing the eggs ahead of time if a woman was having surgery where her ovaries might need to be removed. Another scenario would be freezing eggs in patients transitioning from female to male before they transitioned with medications or surgery. More recently, OC has become more popular for women who wish to proactively freeze their eggs without any medical indications.
Oocyte cryopreservation is done by a reproductive endocrinologist who is specially trained in this field of medicine. It entails a meeting with the doctor to review a patient’s history and then a physical exam. Testing is done to assess a woman’s current ovarian reserve to see if she is a candidate for egg freezing. The testing involves ultrasound and blood work. If a woman is deemed eligible, she then undergoes ovarian stimulation with medication to get multiple eggs to grow in one cycle. Her response to the medications is followed with blood work and ultrasound. Once the egg follicles are deemed “mature” then she is scheduled for an oocyte retrieval which is done under IV sedation in an ambulatory surgical setting. The retrieval is a same day surgical process, and the patient goes home that day. The whole process of stimulation of the ovaries to retrieval on average takes about 2 weeks. After the eggs are retrieved, they are labeled as mature or immature. Only mature eggs can be frozen and used to create a potential future pregnancy.
For now, there is no “expiration date” on when these eggs need to be used. When the patient is ready to use her eggs, an egg thaw date is scheduled and then the eggs can be fertilized with sperm (either donor sperm or her partner’s sperm). The fertilized egg is then grown into an embryo, at which stage it can be frozen and used in a frozen embryo cycle to create a pregnancy. Success rates are highly dependent on the number of eggs retrieved and the chronological age of the eggs.
Women can be reassured that the IVF process needed to retrieve the eggs has been around for decades and is considered a safe procedure relatively free of risks. In IVF, the woman’s age is a major predictor of successful pregnancy and live birth, and this is also true of Oocyte cryopreservation.
Oocyte cryopreservation allows women to have reproductive autonomy in controlling their future so that if they wish they can have a child with whom they are genetically linked.
In the past women had little control over their future fertility. If they waited past the optimal time to conceive, they may have faced a future of infertility and childlessness where their only option would be to pursue adoption or egg donation in order to have a family. Oocyte cryopreservation allows women to have reproductive autonomy in controlling their future so that if they wish they can have a child with whom they are genetically linked. If a patient is contemplating OC, it is important that she make an appointment with a reproductive endocrinologist to review the pros and cons of this procedure.
Melissa C. Yih, MD, is Board Certified in both Obstetrics and Gynecology and Reproductive Endocrinology and Infertility and has been practicing in the NJ area since 2002. Dr. Yih received her undergraduate degree from Wellesley College and her medical degree from The Robert Larner, M.D. College of Medicine at The University of Vermont. She completed her Obstetrics and Gynecology residency and her clinical fellowship in Reproductive Endocrinology and Infertility at New York-Presbyterian Weill Medical College of Cornell University. Her areas of interest include counseling patients regarding fertility preservation options.