For some women, the cause of infertility is found to be diminished ovarian reserve.
While all women run out of eggs as they age, some women run out of eggs faster than they should. There are several potential causes for this condition. Oftentimes it appears to be due to genetic factors, i.e. there is a family history of early menopause. Sometimes the cause is previous ovarian surgery during which all or part of an ovary was removed because of an ovarian cyst or endometriosis. Unfortunately, potentially millions of irreplaceable eggs were also lost during that process. Other factors, such as chemotherapy and radiation therapy for cancer or other chronic medical conditions can also significantly deplete a woman’s egg supply. Often, however, no cause is found. Regardless of the cause, the end result is the same – a significantly reduced chance for pregnancy before the age of 35 and eventually, early menopause.
Ways to measure ovarian reserve combine ultrasound and blood work.
When your TFC physician performs an ultrasound early in the menstrual cycle (typically days 2-4), she can count the number of follicles that are visible in your ovaries. These small follicles are called antral follicles. The antral follicle count gives a clue as to how many total eggs are left in the ovary. In addition to the antral follicle count, a blood can be obtained at the same time in your cycle in order to measure the hormones involved in egg development. These include follicle stimulating hormone (FSH), estrogen (E2), and anti Mullerian hormone (AMH). Follicle stimulating hormone comes from the brain and is the hormone that makes eggs grow and mature. The lower the number of eggs left, the higher the FSH has to rise in order to cause eggs to grow and mature.
A normal FSH is less than 10-12.
It is important to have an estrogen level drawn at the same time as the FSH. The estrogen level should be less than 50 in order to ensure that the FSH level is accurate. If the estrogen level is greater than 50, the FSH level is usually falsely low. A high estrogen level may also be suggestive of diminished ovarian reserve.
There is nothing that can be done to improve ovarian reserve or make more eggs. In some cases, pregnancy can still be achieved, so aggressive fertility treatment should be started immediately. However, for some women the loss of eggs is so severe and the number of viable eggs remaining is so small, that an egg donor is required for fertility treatment to be successful. Diminished ovarian reserve typically progresses to premature ovarian failure and early menopause.
