Dr Gleaton breaks down what AMH is, and if hormonal birth control could be affecting your AMH level or ability to conceive.
By OBGYN and fertility expert Dr. Kenosha Gleaton
If you’re actively trying to conceive or if you’re just looking ahead, you may be wondering what all you should be doing to prepare. If you’ve done any research on fertility testing and treatments, you might have seen anti-Mullerian hormone (AMH) mentioned. AMH can give you some insight into your fertility, but should be interpreted with caution. Your AMH level might even be skewed if you’re taking hormonal birth control pills. Let’s break down the basics.
What is AMH?
AMH is a hormone expressed by granulosa cells of the ovary during a woman’s reproductive years. A gradual increase in AMH levels is observed in girls from the first day of life, with maximum levels observed in women at around the age of 25. In adult women, AMH levels gradually decline as the primordial follicle pool declines with age, becoming undetectable at menopause.
AMH and fertility
Research shows that AMH levels correlate with the number of oocytes (eggs) in the ovaries and can help predict ovarian response during fertility treatments. While AMH has some association with predicting live birth rates during fertility treatment… it doesn’t define fertility and isn’t a conclusive predictor of the chances of conceiving naturally.
Read more about what your AMH levels can and can’t tell you.
The effects of birth control
While no proven relationship exists between oral hormonal birth control and AMH levels, some studies suggest that oral contraceptives reduce AMH levels. Discontinuing oral contraceptive use was also associated with a slight increase in AMH.
Another study found users of hormonal contraceptives had a lower mean AMH level compared to those not on hormonal contraceptives. However, this level seems to be temporary as researchers found AMH levels to be reversible after stopping oral birth control.
The main takeaway: if you’ve checked your AMH level while on hormonal birth control, your level may have been falsely low.
What happens to your eggs when you’re on birth control?
The purpose of hormonal birth control is to prevent ovulation through estrogen and/or progestin. When you are on birth control, an egg is not released from the ovary and is technically “saved”. This doesn’t mean that being on birth control can drastically change your ovarian reserve. Keep in mind the average woman has around 35,000 eggs by age 30, so even 10 years of birth control only “saves” 120 eggs (or 0.4%). Plus, egg quality is as important (if not more important) to your chances of having a baby.
Can birth control affect fertility in the long run?
No! Birth control doesn’t impact fertility in the long-term. A prospective study of 8,500 pregnancies found that 85% of women who never used birth control got pregnant within a year of trying, compared to 89% of women who had used birth control for more than five years. The authors concluded that prolonged use of oral contraception was associated with slightly improved fertility.
AMH levels over time
In general, a typical AMH level for a woman of reproductive age is 1.0–4.0 ng/ml.
One study looked at the median AMH levels (ng/mL) in 2,741 women and found:
- Under 25 = 5.13
- 25 = 5.42
- 26 = 4.91
- 27 = 4.12
- 28 = 4.96
- 29 = 3.87
- 30 = 3.53
- 31 = 3.59
- 32 = 3.44
- 33 = 2.70
- 34 = 2.49
- 35 = 2.58
- 36 = 2.28
- 37 - 1.85
- 38 = 1.66
- 39 = 1.72
- 40 = 1.27
- 41 = 1.26
- 42 = 1.20
- 43 = 0.81
- >43 = 0.72
While there are no definitively proven ways to increase your AMH levels, there are ways to increase your chances of getting pregnant.
Can you take an AMH test while on birth control?
Yes, but because studies have shown that birth control may impact your results, you want to consider this when interpreting your results. If you are looking for a full picture of your ovarian health, you should get a fertility workup with your OBGYN or an REI (reproductive endocrinologist). They will know how the specific birth control you are on may impact your AMH results, and can give you additional insights from other biomarkers including day 3 FSH, day 3 estradiol, antral follicle count, and more.
Where can I have my AMH tested?
You can buy an AMH test online, but if you want the best possible understanding of your fertility, your OBGYN or REI can order an AMH test as part of a larger fertility workup.
Maintaining healthy levels
AMH testing is just one way of determining about how many eggs are in your ovaries. If you’re on oral hormonal birth control, your fertility won’t be affected, but your AMH levels might. If you’ve checked your AMH before while on birth control and felt the number was pretty low, you should try checking again after getting off birth control. But remember, your AMH level is not predictive of your chances of conceiving naturally — and certainly does not define your fertility!
Learn more about fertility, family planning, and more.