FSH and Fertility
Just a warning - this one is science heavy.
When it comes to fertility it’s all about a healthy balance of hormones. One of the hormones that plays a role in healthy cycles and fertility is Follicle Stimulating Hormone, or FSH.
FSH is a hormone produced by the pituitary gland. It’s job is to regulate your menstrual cycle and promote the growth of ovarian follicles. FSH levels naturally fluctuate throughout your menstrual cycle, with higher levels typically seen in the follicular phase, just before you ovulate. Abnormal FSH levels can be an indication of a problem with your reproductive system and can impact your fertility potential. Because of this, testing your FSH can be helpful in determining if this is a factor with your fertility struggles.
Essentially, FSH is the message sent by the pituitary telling the ovaries to produce a bunch of follicles. As the follicles are produced and start to grow, estrogen increases. The estrogen is the signal back to the pituitary gland that the ovaries have done their job and have eggs ready to go.
High FSH levels, particularly in women over 35, are often associated with a diminished ovarian reserve, meaning that the ovaries have fewer eggs remaining. This can make it more difficult to conceive naturally and may also impact the success of fertility treatments such as IVF. In some cases, high FSH levels can also indicate a problem with the pituitary gland or hypothalamus, which can affect ovulation and fertility. I heard a great analogy once that high FSH levels are like the pituitary (boss) screaming at the ovaries (employees) to do their job. The more FSH, the louder the pituitary is yelling. For some reason, the ovaries aren’t responding to the message and so the pituitary keeps amplifying it to get them to listen.
On the other hand, low FSH levels can also impact fertility. Low FSH levels can indicate a problem with the hypothalamus or pituitary gland, which can result in irregular menstrual cycles, anovulation (failure to ovulate), and infertility. Low FSH levels can also indicate premature ovarian failure, which occurs when the ovaries stop functioning before the age of 40, leading to infertility.
We don’t want the pituitary screaming at the ovaries, but we need it telling the ovaries to do SOMETHING. Using the same analogy of boss/employees above, when FSH is low it means either the CEO (hypothalamus) or the boss (pituitary) either fell asleep or stayed home sick, and the employees (ovaries) aren’t getting the memo for what tasks to complete.
A good level of FSH is around or below 7. Above 10 and that means the pituitary is yelling at the ovaries. You also want FSH and LH (luteinizing hormone) to be in a 1:1 ratio.
We need the right messages being sent and received so that our hormones stay in balance, and everyone is confident and clear on their task. Monitoring FSH levels, along with other reproductive hormones and diagnostic tests, can help determine the cause of infertility and guide your steps forward.
FSH can be checked with a blood or saliva test. Your primary Dr can order blood FSH levels, but they likely won’t order saliva testing as it’s not common practice for physicians. A holistic or functional practitioner, as well as a trained nutritionist can order blood or saliva tests and help you understand your levels. This allows them to recommend nutrition and lifestyle changes (and possibly supplements) to support your hormones and overall fertility.
Hormones are just part of the fertility picture. Every hormone has a matching receptor on the surface of the cell that allows the hormone to “connect” and influence the cell. There can also be an issue with these receptors. There can be mutations on the receptor itself that can impact fertility. One example is an inactivating mutation.
An inactivating mutation on a hormone receptor refers to a genetic change that changes the structure or function of that receptor, making it less responsive to the hormone trying to bind to it. Hormone receptors are specialized proteins found on the surface, or within cells, of various tissues in the body, and they play a critical role in managing the effects of hormones on those tissues.
When a hormone binds to its receptor, it triggers a series of signaling events within the cell that can lead to changes in gene expression, cell growth, differentiation, or metabolism, depending on the specific receptor and hormone involved. An inactivating mutation on a hormone receptor can disrupt this process, resulting in decreased or absent signaling activity in response to the hormone. It essentially becomes like trying to open a lock with the wrong key.
This can have various consequences depending on the specific hormone and receptor involved. For example, an inactivating mutation on the follicle-stimulating hormone (FSH) receptor can lead to infertility, as the ovary may fail to respond adequately to FSH stimulation, leading to impaired egg development.
Inactivating mutations on hormone receptors can be inherited or arise spontaneously, and they can vary in severity depending on how much they impair receptor function. Treatment options may depend on the specific disorder and can include hormone replacement therapy, assisted reproductive technologies, or targeted therapies aimed at restoring or bypassing the signaling pathway affected by the mutation.
A recent study in Nature Communications, Mechanism of hormone and allosteric agonist mediated activation of follicle stimulating hormone receptor, 2022, studied the receptors and mutations to determine if it would be possible to improve the receptor function using FSH receptor targeting drugs to treat infertility. The study showed that this was a possibility and paves the way for new drugs that will help women whose fertility struggles are stemming from these receptor issues.
If you are still with me, thanks for sticking through it! I know this was a science heavy blog, but part of what I hope to show you is that infertility can be from several different things. It isn’t always a hormone or receptor issue that needs new shiny drugs to overcome. It isn’t always because you are “out of eggs”, “too old” or “overweight”. There are lots of things you can do naturally and holistically to improve fertility. It always starts with nutrition and lifestyle changes. Real, nutrient dense, whole food, plenty of mineral and electrolyte rich water, good gut health, balanced blood sugar, sleep, stress, and movement.
My job is to help walk you through what changes would most benefit you right now, and to uncover your root causes. Spending time working on the foundational aspects of your health is important even if you are preparing for IVF. Preconception nutrition planning sets you up for greater success, an easier pregnancy, and a smooth postpartum.
