Ask Dr. Pat

Dr. Pat Consults: Egg Freezing and Your Future Pregnancy—What Women Need to Know

Patricia Yarberry Allen, M.D. is a Gynecologist, Director of the New York Menopause Center, Clinical Assistant Professor of Obstetrics and Gynecology at Weill Cornell Medical College, and Assistant Attending Obstetrician and Gynecologist at New York-Presbyterian Hospital. She is a board certified fellow of the American College of Obstetrics and Gynecology. Dr. Allen is also a member of the Faculty Advisory Board and the Women’s Health Director of The Weill Cornell Community Clinic (WCCC). Dr. Allen was the recipient of the 2014 American Medical Women’s Association Presidential Award.

According to studies, the total number of ocytes, the medical term for “eggs,”a woman over the age of 36 needs to have frozen—to have a reasonable chance of having a baby—is over 30 eggs.

Dr. Patricia Yarberry Allen is a collaborative physician who writes a weekly Medical Monday” column for Women’s Voices for Change.  (Search our archives for her posts, calling on the expertise of medical specialists, on topics from angiography to vulvar melanoma.)

This week, Dr. Pat has asked Dr. Glenn Schattman — an Associate Professor at the Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine at the Weill Medical College of Cornell University — to unpack the complicated and evolving process of “egg freezing.”


Dear Dr. Pat,

My daughter, Lydia, is thirty-two years old. She is a wonderful young woman who owns a small business and works long hours to make it successful, has lots of friends from college and has made new friends in the city where she lives. She should be having a great life. Instead, she has become more and more anxious about finding a life partner. She has been a bridesmaid fourteen times and each time she hears that a colleague or friend is getting married or having a baby, it throws her into a state of near hysteria. This is not her real self. Lydia is like many of the young women I hear about from other mothers: attractive, interesting and kind, but unable to find a man who is willing to consider settling down. We have begun to think about encouraging our daughters to consider “egg freezing” so that they can date without the pressure of the biological clock. What can you tell me about this process? 



Dr. Pat Responds:

Dear Joan,

This is a complicated psychosocial, ethical and medical question. The idea of “egg freezing” gives hope to many women who are having difficulties in finding a partner or who will have ovarian failure from chemotherapy or other medical problems. However, it is viewed negatively by many others who feel that egg freezing is somehow unnatural, much like the reactions to the first “test tube baby”.

As physicians, we have an opportunity to answer your question to raise awareness about reproductive decision-making. In this post, we will not comment on the difficult choices that women may make about investigating or choosing this option to maintain the ability to have children when they are older.  Instead, we will explain the science and the reality of “egg freezing” as it exists in 2015.

I have asked Dr. Glenn Schattman, Associate Professor at the Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine at the Weill Medical College of Cornell University, to answer this very timely question. The scientists in the speciality of reproductive medicine created IVF (In Vitro Fertilization). The first child born from this technology, Louise Brown, will be 37 years old on July 27!  The reproductive physicians and scientists in this field have now created a way for the eggs in a woman’s ovaries to be extracted and safely preserved until she is ready or able to become pregnant. However, it is important that women understand the current success rate of this evolving reproductive technology as they make decisions about delaying pregnancy. There are some medical terms that are unavoidable in the discussion of this complex process. As you read Dr. Schattman’s  response, refer to the list below for an explanation of the terms used in his thorough explanation of this evolving technology.  I must warn you that this is not medical “lite” information.

  • Oocytes – medical term for “eggs”
  • Fecundity – the probability of achieving pregnancy each cycle.
  • Antral follicle counts – potential eggs available each cycle.
  • Vitrification – ultra rapid freezing of the egg.
  • Cryoprotectants – a substance used to protect biological tissue from freezing damage.

Dr. Pat


Dr. Glenn Schattman Responds:

Fertility Preservation

Women are endowed with a finite pool of oocytes (eggs) that are gradually depleted, peaking at approximately 5 million oocytes at birth with approximately 500,000 oocytes remaining at puberty. While women continue to ovulate until the peri-menopausal transition in the early-to-mid 40s, fecundity (the probability of achieving pregnancy each cycle) diminishes after age 35 due to increased risk of chromosomal abnormalities in the remaining eggs.

Human reproduction is, by nature, an inefficient process. For younger women (under the age of 35) attempting pregnancy for the first time, the chances for conception each cycle is approximate 25% per month for the first few months and declines steadily from that peak. Women attempting to start families after age 35 have a higher probability of not being able to conceive. Additional risk factors for infertility and earlier menopause include a family history of early menopause, smoking, ovarian surgery and treatment with pelvic radiation and/or chemotherapeutic agents. More women are waiting to have children later in life, and with over 100,000 women of reproductive age in the United States receiving cancer diagnoses each year, infertility is not an uncommon problem.

In addition to these complications , there has been increased interest in the preservation of a woman’s ability to have children beyond the limits of when natural reproduction would be unlikely, but, before the complications of pregnancy due to advanced age would be a risk to either the mother or baby. Egg freezing appears to be one solution to this problem. In past techniques, because of the oocyte’s large size and high water content, freezing eggs resulted in ice crystals, which would destroy the cell. Modern freezing techniques use cryoprotectants (a substance used to protect biological tissue from freezing damage) to remove water from the egg and reduce ice crystal formation. As technology has improved, ultra rapid freezing of the egg, i.e. vitrification, has resulted in excellent success rates, similar to those in IVF where fresh eggs are used (eggs that have not been frozen). Because the eggs with vitrification aren’t technically “frozen,” they are also not “thawed.” Rather, they are “warmed” to bring them back to body temperature. Because of “hardening” of the protective shell around the egg as a result of this procedure, intracytoplasmic sperm injection (ICSI), the injection of a single sperm directly into the egg, is used to assist fertilization.

Next Page: When to Consider Egg Freezing

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  • Pregnancy Guide June 29, 2015 at 9:45 pm

    wow that was a very detailed article, thank you so much that really helpful.

  • Megan Riddle June 25, 2015 at 2:26 pm

    A timely and well-balanced article. There are many reasons women may not be ready to have children in their 20s and early 30s – focusing on career, finding a spouse. For those with means, “egg freezing” can offer a certain level of insurance. I do wish the financial cost weren’t so high and it was available to more women. Maybe, as with many things, as the technology moves forward, the cost will come down.