Doctors can now test your AMH (Anti-Muellerian Hormone) to get a picture of your ovarian reserve. AMH is secreted by the follicles your ovary produces every month as you "recruit" multiple eggs. Your body then releases what it thinks is the "best" one around day 14 of your cycle. Naturally, as women age, your body has used up not only more of the eggs you have, but the highest quality eggs as well.
For the average woman, ovarian reserve declines to the point where you start seeing a real difference around age 35. By 37, most women have about half the chance of getting pregnant every month as they did in their early 20s. And for most 40 year olds, unfortunately, there is a greater chance of having a miscarriage and an embryo with chromosomal abnormalities than a successful pregnancy.
How do you know if you are the "average woman"? An easy blood test will measure your ovarian reserve. Most women with low ovarian reserve do produce enough hormones to get their periods. So having a regular period does not tell you what your egg reserve is like.
What causes early fertility loss?
There are 12 KNOWN causes of diminished ovarian reserve:
Age. This is the most common cause and for most women, fertility begins to decline rapidly around age 37.
Smoking. 60% of women with a history of heavy smoking for 15 years or more will experience menopause by 40 and a loss of fertility around 32.
Heavy alcohol or drug use.
Previous ovarian surgery, even minor procedures for benign conditions.
Endometriosis, especially when it affects the ovary.
Some autoimmune diseases, such as lupus.
Infectious diseases, such as childhood mumps.
Genetic mutations that predispose you to low reserve. For most patients, these genetics will not be detected until infertility becomes an issue.
Familial predisposition, such as your mother experiencing early menopause, and certain inherited genetic conditions such as Fragile X.
Unknown causes (idiopathic). There are patients who are simply born with a lower number of eggs or whose bodies use the eggs up more quickly.
Medical treatments such as radiation and chemotherapy.
Some environmental toxins may cause loss of fertility. Some suspected toxins include ambient radiation and BPA found in plastics.