I want to dive into deeper detail with testing serum (blood) for hormones. When I’m testing blood for hormones, it is a snap shot in time – That means that whatever your hormone levels happen to be the minute the blood was drawn, those are the levels I will be receiving in the report. This isn’t great for something that is constantly in flux throughout the day as well as the month. There isn’t a perfect testing method, however we can still gain valuable information if the tests are performed on certain days throughout the menstrual cycle.
Pituitary hormones: LH and FSH – these two are typically tested around day 3 of the menstrual cycle when I’m assessing fertility, ovarian response and ovarian reserve. These hormones are coming from the pituitary gland in the brain to signal the ovaries to start follicular development (FSH – follicle stimulating hormone’s main job) and then to trigger ovulation (LH – luteinizing hormone’s main job). The more “responsive” the ovaries are, the lower these numbers are going to be on day 3 –this is a good thing. During peri-menopause and into menopause we see a gradual increase in LH and FSH values – as the pituitary has to work harder and harder in order for the ovary to respond until eventually the ovary stops responding. These hormones also need to be considered in relation to estradiol (a form of estrogen that is tested). LH and FSH values can also be useful when comparing their values to each other – An LH to FSH ratio that is greater than 2:1 can hint towards possible PCOS – to then be followed up with a myriad of other hormone + metabolic tests.
Ovarian hormones: Estradiol + Progesterone
Estradiol– this is tested on day three with LH and FSH (as I said earlier, this value is looked at with respect to the LH and FSH values). This is early on in the cycle when estrogen is relatively low in the body, so day 3 is assessing a baseline estrogen / ovarian response at the start of the cycle, and it can be assumed that estrogen will increase from that baseline. We want a healthy and responsive baseline.
Progesterone– this is tested 7 days prior to next expected menses. The actual numerical value of progesterone is less important than the fact that it is just present. I’m looking for a progesterone at least greater than ~10 nmol/L in order to confirm that yes, ovulation happened that cycle. Progesterone is a tricky one to test, because it is going to also have a pulsatile secretion – meaning it will vary throughout the day as well as cycle. As long as your progesterone level is above the threshold to confirm ovulation, I don’t read to heavily into the numerical value.
The long short of it is – if this lab work is done during the appropriate time in the cycle and combined with the clinical picture –IE signs and symptoms of hormones, fertility history, etc. it can provide valuable insight into what is going on biochemically with respect to your hormones!
Have you had your hormones tested?