fertility news

A woman has her lifetime supply of eggs (about 7 million) in her ovaries before she is even born and each month loses some, so by the time she is born the number has dwindled down to approximately 1 million. This steady decline continues so that approximately 300,000 remain as a woman enters puberty and the supply of eggs is depleted by the time a woman enters menopause.

Eggs grow in fluid filled sacs in the ovary called follicles which contain cells that support the growth and development of the eggs as well as secreting the hormones necessary for ovulation. There is a huge difference between the number of available eggs in the ovaries and the numbers that actually develops to maturity and are released during ovulation.

For most women the number of available eggs as well as the quality of the eggs declines as she gets older, a condition commonly referred to as diminished ovarian reserve (DOR). There may be a new tool in the reproductive endocrinologist’s (RE) arsenal to diagnose diminished ovarian reserve. Anti-mullerian hormone (AMH) is produced in the cells of developing ovarian follicles and some research suggests that measuring this hormone may be an earlier marker of a woman’s reproductive potential.

Until now the tests available to determine ovarian reserve have only been able to tell the clinician when the egg supply is almost gone. At that point it may be too late. AMH may be a marker for a woman’s egg supply that can be measured earlier in her reproductive life cycle.

Using a blood test to measure AMH levels as a marker for ovarian reserve has been done routinely in Europe. In the US however the test is not as popular. A recent article in the Wall Street Journal (WSJ) (April 22, 2008) suggested the lack of uniform measurement standards is the reason the test is not used as routinely. According to the WSJ tests such as this come under Food and Drug Administration (FDA) oversight and the systems used to measure the hormone have not yet met the FDA criteria for clinical use. The author goes on to say the FDA however has not restricted its use and physicians in 24 US cities are currently using the test.

Articles such as this appear in mainstream publications because more women are delaying childbearing to pursue education and career opportunities. When they are ready to start a family these women often turn to assisted reproductive technologies such as intrauterine insemination (IUI) and in vitro fertilization (IVF) to get pregnant. The Society for Assisted Reproductive Technology (SART) of the American Society for Reproductive Medicine (ASRM) reported more than 48,000 cycles of in vitro fertilization were done in 2006 on women 35 and older.

Tests to measure ovarian reserve are routinely ordered by infertility specialists to assess a woman’s reproductive potential. The results of these tests help the physician determine the best treatment options. One of these tests measures the level of follicle stimulating hormone (FSH) on day 3 of woman’s menstrual cycle. FSH is secreted by the pituitary gland to stimulate the growth of the follicle. In the early part of the menstrual cycle the level of FSH should be low; high levels are associated with diminished ovarian reserve. The accuracy of this test however is limited to when in the cycle it is done since FSH levels rise in the first half of the menstrual cycle and should be measured at their lowest point. One suggested advantage of AMH testing is the convenience of doing the test anytime since AMH levels remain constant throughout the menstrual cycle.

Another test of ovarian reserve measures the number of small follicles present in the ovaries in the early part of a woman’s menstrual cycle. Physicians routinely perform trans-vaginal ultrasounds around day three of the menstrual cycle to count the number of follicles present. This is known as a basal antral follicle count (BAFC).

Since 2002 multiple studies have been published regarding the use of AMH testing. A recent study found a correlation between low AHM levels and elevated FSH levels. The authors concluded that both are indicators of ovarian reserve. Another study found a correlation between low serum AMH levels and poor ovarian response to stimulation in IVF cycles and although this finding was replicated by a group of Dutch researchers they found it neither correlated with embryo quality nor predicted the probability of pregnancy.

A 2007 meta-analysis looked at 30 published studies and found that AMH is as accurate as BAFC in predicting poor ovarian response and non-pregnancy. The authors maintain that the inability to predict pregnancy outcome was not a surprise since both tests- AMH and BAFC are thought to represent only the size of the egg pool. The advantage of AMH testing for patients (in their opinion) is that blood testing is already routinely done in an infertility work-up while a BAFC requires the use of an experienced ultrasonographer.

In conclusion, nothing can turn back a woman’s biological clock. However AMH testing may help clinicians diagnose problems with ovarian reserve earlier in a woman’s reproductive life cycle- before it’s too late. If you are trying to get pregnant and have been unsuccessful schedule an appointment with your health care provider as soon as possible.

References:

Broer S, Mol B, Hendriks D, Broekmans F. The role of anti-mullerian hormone in prediction of outcome after IVF: comparison with the antral follicle count. Fertil Steril 2008; [E-pub ahead of print].

SART 2006 Clinic Summary Report. Available at: https://www.sartcorsonline.com/rptCSR_PublicMultYear.aspx?ClinicPKID=0

Seifer D, MacLaughlin D, Christian B, Feng B, Shelden R. Early follicular serum müllerian-inhibiting substance levels are associated with ovarian response during assisted reproductive technology cycles. Fertil. Steril. 2002; 77: 468–471.

Singer T, Barad D, Weghofer A, Gleicher N. Correlation of antimüllerian hormone and baseline follicle-stimulating hormone levels. Fertil Steril 2008; [E-pub ahead of print].

Smeenk J et al. Antimüllerian hormone predicts ovarian responsiveness but not embryo quality or pregnancy, after in vitro fertilization or intracyoplasmic sperm injection. Fertil. Steril 2007; 87: 223-226.

te Velde E, Pearson P. The variability of female reproductive aging. Hum Reprod. Update, 2002; 8: 141–154.

van Rooij I, et al. Serum antimüllerian hormone levels: a novel measure of ovarian reserve. Hum Reprod 2002; 17: 3065–3071.

Won Tesoriero H. A New Measure in Fertility Testing. The Wall Street Journal April 22, 2008. Available online at: http://online.wsj.com/public/article/SB120882227501033057-
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