When trying to assess a woman’s fertility potential, physicians often conduct an AMH test. This test offers information about a woman’s egg quantity. However, hormonal contraception can skew the results of this screening. Dr. Heather Cook explains how to get an accurate outcome.
AMH testing is increasingly being used in general OB/GYN practice as a screening tool to help women assess their ovarian reserve and future fertility potential. Although not necessarily predictive of fertility outcomes, it can help identify women with early diminished egg number. Originally, it was thought that AMH was very consistent throughout cycles and was not altered by outside factors. Over the past few years however, it has been recognized that AMH can be altered via the use of hormonal contraceptives. Since many young women who are not actively trying to conceive tend to be on some sort of hormonal contraception, this relationship is important to understand when ordering AMH levels for screening purposes.
Studies have been mixed on whether AMH is decreased with hormonal contraceptive use and to what degree. The larger studies seem to agree that in women actively using hormonal contraception, AMH levels tend to be lower. This effect is usually not until after the first 6 months of use and the decline appears to be more significant in long-term users. Fortunately, AMH levels seem to rebound after cessation of the hormonal contraceptive.
Most of the original studies looked only at combination oral contraceptive pills, but a recent study published in Fertility and Sterility looked at the relationship of AMH in women using multiple types of hormonal contraception. AMH levels in this study were 25% lower in current hormonal contraceptive users than in nonusers across all types of hormonal contraception. When looking at AMH levels 1-year after hormonal contraceptive cessation, levels between never-users and previous-users showed no differences.
Clinically in our own practice, we do see significant declines of AMH levels in women that have been on long-term hormonal contraception. Personally, I feel that the longer a woman has been on hormonal contraceptive suppression, the lower the overall antral follicle count and AMH levels are. Generally in this case, we would not consider the AMH level while on birth control pills to be accurate. I normally recommend a “washout” period from the hormonal contraception of at least 3 months. AMH levels in general, tend to rebound nicely by that point and the patients with true diminished ovarian reserve can be identified. In women who have been on hormonal contraception for extremely long time periods (10+ years), the AMH level seems to take longer to come back to baseline.
Overall, I feel that if AMH is being used for screening purposes, drawing the level when off hormonal contraception is ideal. If a normal level is obtained while on contraception, this can at least give the patient reassurance that the egg count is not low and likely may be even higher once stopping birth control. In order to truly diagnose diminished ovarian reserve however, an accurate AMH should be obtained when off all hormonal contraception.
If you are interested in an infertility evaluation which includes AMH testing, please call 843-883-5800 or click here to schedule an appointment.