What is Ovarian Reserve?

Regular menstrual cycles or having a period every month does not mean that your ovarian reserve (OR) is ‘adequate’, especially if you are in your late thirties or older. As you enter your mid-thirties, there is a significant decline in your fertility. This may be due to the decline in quantity and quality of your oocytes or eggs. Oocyte number peaked while you were in your mother’s womb at about 6 or 7 million. It declined to about 1 to 2 million at birth, 3-400 thousand at your first period, 25,000 at age forty, and 1 thousand at age 50 (the average age of menopause). Nothing stops this decline in number of eggs. Not pregnancy. Not birth control pills. Not skipping periods. Nothing. The eggs are pre-programmed for ‘cell death’, which is in part related to the time your mother experienced menopause. From a fertility standpoint, the clock really is ticking. I should say from the outset that a decrease in OR does not translate in to increase in your age, meaning you are not ‘older’ simply because your OR is ‘older’ or low.

Causes of low ovarian reserve
Your ovarian reserve can be depleted by:

• Smoking
• Surgery
• Endometriosis (which can run in families)
• Treatments for cancer: radiation and chemotherapy (perhaps along with surgery)

Interestingly, if one ovary is removed the other ovary does not speed into menopause sooner, but obviously, your OR would be reduced

Should you get tested?
Women interested in having children but not prepared to do so by age 30 may want to keep tabs on their ovarian reserve, if possible. And it is possible. (Although this is not the standard of care nor will your insurance company necessarily cover it). If tests show that your OR is normal, then I suggest repeating the test every 2-3 years. Know that test results are not absolute and are not always accurate. Someone who thoroughly understands the results and their limitations should interpret them. But what if you checked your OR and it was getting low? What would you do? That is the question to ask yourself. If the answer is ‘nothing’, then I suggest not doing the tests to avoid needless anxiety.

If you are subfertile (your ability to become pregnant is somewhat of a challenge), then an awareness of your ovarian reserve is even more important, especially if you fit into one of these categories:

• You are 35 or older
• You have ‘unexplained infertility’
• There has been a possible insult to your ovaries from the causes listed above.

In my next blog post, I will go over the ovarian reserve testing process.

Henry Bohler, Jr., M.D. ‘Major’ Bohler is Board Certified in Obstetrics and Gynecology and Reproductive Endocrinology and Infertility. He is also Medical Director at the University of Louisville’s Fertility Center, University OB/GYN Associates. Besides having a keen interest in IVF, Dr. Bohler other interests include polycystic ovary syndrome, recurrent pregnancy loss, and endometriosis.