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FSH levels and fertility

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“Your tests confirm your age. They’re not terrible; but they’re not great,” my gynaecologist told me. Well, der, I know how old I am, which is why I’m having these tests done to start with (is what I wanted to say to him, but I didn’t).

Trying to conceive at what is termed *cough, choke* ‘advanced’ age was never going to be easy, but I was determined to try anyway.
I knew the odds were stacked against me, being 40, but I was not deterred.
Armed with a dogged determination and the internet as my new best friend, I set out to do my research on all things having-a-child-at-the-age-of-forty-related.

I started with the FSH levels. You can go to your local GP and ask for a blood test to check your follicle-stimulating hormone levels. Or your GP can refer you to a place that will do them for you. It’s worth getting this tested, as it is the best indicator of what your ovarian reserve looks like.


What is FSH?

It is a hormone that regulates the reproductive process in women’s bodies. It stimulates the immature follicles in the ovaries, each of which surrounds an oocyte, or egg.

At the beginning of a woman’s menstrual cycle there is a surge, on about day three, of FSH levels, which initiates the growth of between five and seven primordial ovarian follicles.
The FSH will also stimulate the body to produce more oestrogen, which in turn increases the production of luteinizing hormone (LH).

During this phase, a couple of days before the increase of LH levels, one of these follicles will become the most dominant.
While oestrogen levels continue to rise, FSH levels drop off again, causing the weaker follicles to die off, while the dominant follicle grows.

The high oestrogen levels continue for about six days, preparing the uterus and creating a more hospitable environment for possible sperm.
The LH levels then surge, stimulating the meiosis, or cell division, of oocytes in the dominant tertiary follicle.
Roughly 30 hours after the LH surge, the follicle ruptures, releasing an egg. This is called ovulation.

This follicular cycle lasts about 14 days, with day 1 being the first day of the menstrual cycle.

How FSH levels are measured

FSH levels should be taken between days two and three of the menstrual cycle.
There are different FSH levels for women at different ages, due to the amount of follicles we have at those stages.
It is important to remember that what is seen as a ‘normal’ FSH level for a woman of, say 41, will be abnormally high for a woman in her early 30s.

High FSH levels in a woman of ‘normal’ fertility age can be caused by a number of things:

  • Premature Menopause
  • Low or poor ovarian reserve – also called Diminished Ovarian Reserve
  • Turner Syndrome – a chromosomal problem
  • Genetics

Example of FSH levels at different ages

Age (years)FSH level in mlU/mL









FSH levels as we age

As we get older, the number of primordial follicles in our ovaries diminishes while the Follicle-stimulating Hormone rises. A high FSH level is therefore usually an indicator of diminished ovarian reserve (DOR).
By menopause, any of the small secondary follicles that we do have remaining, no longer have FSH receptors.

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What this means for fertility

The good news is that, despite high FSH levels – up to a certain point - women can still fall pregnant.
Research at the Centre for Human Reproduction (CHR) has proven that using the DHEA supplement at least 6 weeks before an IVF cycle can dramatically increase the chance of falling pregnant, despite high FSH levels and DOR.
Remember that a high FSH level is the indicator of Diminished Ovarian Reserve, and not the cause. The DHEA is treating the actual cause of FSH, which is DOR.

FSH levels can be lowered as well. Some doctors do believe that lowering your FSH level can improve your chances of falling pregnant.
A well-known herb called Vitex Agnus Castus, also known as Vitex, Chaste Tree or Chasteberry, is known to lower FSH levels.


A personal note

My FSH levels were 11.04. Not great, as my gynaecologist said, but not terrible either. Those numbers are still ‘workable’ in fertility-speak! I decided to take Vitex and DHEA to better my chances. I do believe the Vitex lowered my FSH levels, but in the end, the DHEA was what improved my egg quality and quantity.

Please note: I am not a doctor or healthcare practitioner. I do not prescribe treatment, nor speculate on a treatment for anyone. All people are different, and will have different needs. This article is based on my research into FSH levels and pregnancy at an advanced age.
The DHEA and Agnust Castus worked for me and my FSH levels lowered down to a very good 5.0.


Sunny on August 25, 2015:

Do you have a blog? Is there a way to follow your progress?

Ellie on February 01, 2015:

Hi - I just wondered if you knew if FSH has any effect once you actually are pregnant?


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