Nico & Nati

How Do We Test Ovarian Reserve?

Ovarian reserve refers to the presence within the ovaries of follicles (fluid-filled sacs) containing healthy eggs in excess of the single dominant follicle destined to ovulate in a spontaneous cycle. Women whose ovaries possess good ovarian reserve typically respond to ovarian hyper-stimulation with FSH (What is an Ovulation Induction?) by developing multiple growing follicles and mature eggs capable of establishing a healthy pregnancy. Women with reduced reserve typically develop very few follicles even with higher doses of FSH injections. Even more importantly, multiple studies have established that women with diminished ovarian reserve (DOR) are much less likely to achieve a live birth than women with other infertility factors when undergoing IVF and other fertility therapies.

The graph below clearly illustrates that women with diminished ovarian reserve (DOR in red) had about half the live birth rates achieved by patients with most other diagnoses (adapted from the national CDC Report on ART for 2005). Thus, next to the age factor, which itself is closely related to ovarian reserve (What is Age Factor?), reduction in ovarian reserve is the greatest determinant of the success of infertility treatment in women using their own eggs.

Live birth rate per cycle in women with different infertility factors
undergoing IVF with their own eggs

Ovarian reserve is assessed hormonally and anatomically. In our program all patients have a baseline cycle day 2,3 or 4 FSH and Estradiol blood tests. FSH levels above 10 mIU/mL and/or  Estradiol levels above 80 pg/mL are indicative of reduction in ovarian reserve.  High resolution vaginal ultrasound of the ovaries is used to determine the antral follicle count which is an anatomical correlate of ovarian reserve. Unless small antral follicles are present within the ovaries, fertility medications cannot make them grow and the woman will not exhibit the multi-follicular response which is key to the success of IVF and other treatments.

Ovary with small antral follicles (normal reserve)

Ovary without small antral follicles (reduced reserve)

When the day 3 FSH/Estradiol and ultrasound examination do not agree a dynamic hormonal test known as clomiphene challenge may be helpful. In this test cycle day 2, 3 or 4 FSH/Estradiol are followed by oral clomiphene 100 mg daily on days 5-9 and the FSH/Estradiol tests are repeated seven days after the initial test. Under the stress of clomiphene (which is an anti-estrogen binding to estradiol receptors) the pituitary gland releases extra FSH hormone which in turn should hyper-stimulate ovaries possessing normal reserve to initiate production of several follicles each of which releases estradiol thus ultimately lowering the FSH level by cycle day 10. A significant percentage of women with diminished ovarian reserve exhibit normal day 3 FSH but markedly elevated day 10 FSH – a finding which carries similar prognostic implication to elevated baseline day 3 hormones, i.e. a much lower live birth rate regardless of the treatment.

The main reason for ovarian reserve testing is to define the exact likelihood of successful conception for each infertile couple so that they have best information in order to make an informed decision about different treatment options. In addition the information may be of value in selecting ovarian stimulation regimen best suited for an individual patient. Women with severely reduced ovarian reserved, especially if it is associated with advanced age, are much more likely to achieve a successful birth using donor eggs (Donor Egg Program).