What is Anti-Mullerian Hormone (AMH)?
In the first trimester a growing fetus has two ducts, Mullerian (female) & Wolffian (male) that develop into reproductive organs depending on which chromosomes are present i.e. XY Male & XX Female.
The male fetus produces a hormone in the testicles called Anti-Mullerian Hormone (AMH) that stops the development of the Mullerian Duct but keeps the Wolffian allowing the male organs to grow. Since females have no testicles, no AMH is produced at this stage which allows the development of the uterus etc. In females AMH is produced later by the ovarian follicles and correlates with the number of antral follicles in the ovaries.
How is AMH used in IVF?
For women undergoing IVF the treatment protocol and drug dosage are chosen by multiple factors (age, FSH levels, previous response to ovarian stimulation etc), using AMH levels to compliment this process.
Low AMH levels
Low AMH levels indicate a diminished ovarian reserve, potentially resulting in a poor response to fertility drugs. This does not mean a reduced success rate, merely that a short protocol, with no down regulation, should be chosen to maximise the response to ovarian stimulation.
High AMH levels
High AMH can signify polycystic ovaries and an increased risk of OHSS. These women fall into 2 groups:
- patients with a very high AMH are often slow to respond in the first few days of stimulation and need to be very carefully monitored, with blood tests and scans, to avoid over stimulation in the second half of the cycle. A follicular protocol, with just a short period of down regulation may be selected to avoid this problem
- patients whose levels are less elevated, who have a regular menstrual cycle and who respond better to ovarian stimulation. In this case a luteal protocol is generally preferred
Does AMH affect my ability to get pregnant by IVF?
It is important to understand that AMH is just another tool available to us and although a low AMH level can be devastating news, it does not reflect egg quality (age and other factors do this) or a woman’s ability to get pregnant. It merely indicates how well she may respond to stimulation.
Neither high nor low AMH levels correlate with time to pregnancy
