Definition - What does Ovarian Reserve mean?
Ovarian reserve refers to a woman's available reserve of healthy eggs. Healthy eggs are those which are well-equipped to produce a healthy pregnancy, whereas so-called unhealthy eggs are those eggs with genetic or other problems that mean they are unlikely to develop into a healthy pregnancy. Calculations of ovarian reserve attempt to take into account both the number and health of a woman's egg cells, with the goal of predicting her chances of a healthy pregnancy.
FertilitySmarts explains Ovarian Reserve
Because eggs are small and concealed within the ovary, it is impossible to directly count a woman's number of healthy eggs. Some approaches to determining ovarian reserve attempt to use transvaginal ultrasound (TRUS) to count the number of follicles present in the ovary. However, ultrasound is not always a reliable method of imaging at that level of detail.
Other ways to try to establish a woman's ovarian capacity include:
- Testing blood levels of follicle-stimulating hormone and estradiol, which seek to determine whether a woman's ovaries are approaching menopause
- Testing blood levels of the anti-mullerian hormone, which is produced by ovarian follicles which are early in their development
- Measuring how strongly a woman's ovaries respond to the hormones used in in vitro fertilization (IVF) treatments, which may reflect her total number of available eggs
As a general rule, ovarian reserve decreases with age. This is due to a combination of the body 'spending' eggs through routine ovulation, and the ovaries aging and preparing for menopause. Young women with certain reproductive health problems may start out with smaller than the normal reserve of healthy eggs, and some women's reserves decrease more quickly than others with age.
The rate of decrease of a woman's ovarian reserve is thought to accelerate after the age of 35, and continue accelerating until menopause. Women over 35 can still conceive and carry healthy pregnancies, but conception may take longer and rates of complications may increase as their ovarian reserve continues to decrease. For this reason, seeking assistance is often recommended after 6 months of trying to conceive for women over the age of 35.