At birth, women have 1-2 million eggs. This number slowly decreases throughout life. At puberty, a woman has approximately 250,000 eggs, in her 20’s this number decreases to 100,000, in her 30’s it’s down to 10,000, in her 40s as low as 1,000, and by the time she reaches menopause she will have no functional eggs left. As these numbers decline, so does the quality of those eggs. As a result, the ability to become pregnant decreases and the rate of miscarriage increases as a female ages. For example, a classic French study done with women using donor sperm showed a 74% pregnancy rate with up to 12 inseminations for women younger than 31 years old versus 54% for women over 35. Similar trends are seen with embryo transfers resulting in live births, 44.9% for women under 35 and 26.6% for women 38-40 years old. The rate of miscarriage also increases as women age from 11.4% in women 33-34 years old compared to <45% for women 41-42 years old. For this reason, it is very important to evaluate egg health in trying to become pregnant, especially if you are over 33 years old, have unexplained infertility, have menopausal symptoms (such as shortened menstrual cycles or hot flashes), or have had previous ovarian surgery.
In the early follicular phase of a woman’s menstrual cycle, specific hormones can be measured in the blood to provide an approximation of how many eggs the ovaries have and if they are still healthy. Follicle Stimulating Hormone (FSH) and Estradiol levels are measured by a simple blood draw. Elevated levels of FSH and Estradiol, during this time, can indicate a decreased ability to achieve live birth compared to someone with normal levels at the same age.
There is one other blood test that can be drawn at any time during a women’s cycle that corresponds to egg health. This blood test is an anti-mullerian hormone (AMH) level. AMH is released by the granulosa cells of the follicles, so it corresponds to the antral follicle count. In general an AMH level >2 is normal with healthy ovarian reserve and
A transvaginal ultrasound can also be done in the early follicular phase to count the number of small follicles (2-10mm in size) on each ovary. The number of these follicles reflect underlying egg supply and the ability of those eggs to be recruited for ovulation. Lower resting or antral follicle counts correspond with decreased egg health and diminished ovarian reserve.
The evaluation of egg health and identification of diminished ovarian reserve can provide good insight as to a woman’s chances of becoming pregnant and the likelihood of having a miscarriage, assuming other factors that effect fertility have been evaluated and are within normal limits. It can also guide providers to select appropriate fertility treatments and plan what is best for that patient. For patients with DOR, unfortunately it is not reversible. However, there are some treatment options.
1) DHEA, a medication that helps make eggs more responsive to recruitment
2) In vitro fertilization with genetic testing of embryos prior to transfer
3) Donor egg in vitro fertilization (IVF)
For this reason, egg health testing is a crucial part of the infertility work up and plan.
– ASRM and ACOG. Age-Related Fertility Decline. Fertil and Steril 2008
– ASRM, Egg Health Testing asrm.org/detail.aspx?id=1905
– ASRM Practice Comittee. Aging and Infertility in Women. Fertil and Steril 2006
– ASRM, Prediction of Fertility Potential (Ovarian Reserve) in Women asrm.org/Prediction_of_Fertility_Potential_Ovarian_Reserve_in_Women/
– Strauss III and Barbieri, Yen and Jaffe’s Reproductive Endocrinology, 5th ed. 2004
Contact: Contact Conceptions Fertility Clinic at 303-794-0045 or view our contact us page