Blood Tests & Fluctuating Hormones

A health care provider will utilize blood tests to determine if a woman is actively in menopause. However, these blood tests may not be the most reliable means of tracking perimenopause in women.

 Perimenopause, also known as the menopausal transition, is the period leading up to menopause when a woman's ovaries gradually produce less estrogen, causing menstrual cycles to become irregular and menopause-like symptoms to appear. This phase can last several years and ends one year after the final menstrual period.

 In women, follicle-stimulating hormones (FSH) are vital in sexual development and reproduction. The pituitary gland produces this hormone, which affects ovary function. This integral hormone also has the lead role in a woman’s menstrual cycle. 

 Relating specifically to menopause, many women may incorrectly assume that a low FSH number means good things. However, it is a high level of FSH that is associated with menopause because it marks a decline in ovary function.

 According to The Cleveland Clinic, before a woman enters perimenopause, follicle-stimulating hormone (FSH) levels typically fall within the normal reproductive range of 4.7 to 21.5 milli-international units per milliliter (mIU/mL) during the menstrual cycle. These levels fluctuate throughout a woman’s cycle, with a slight rise in the follicular phase to stimulate follicle development and estrogen production, followed by a decrease in the luteal phase, or the period of the menstrual cycle that occurs after ovulation and before menstruation, typically lasting around 14 days..  

 Once a woman enters menopause, due to the ovaries ceasing to produce significant amounts of estrogen, the feedback loop to the brain is disrupted. Estrogen no longer inhibits FSH production, leading to a significant and sustained increase in FSH levels. Postmenopausal FSH levels typically range from 25.8 to 134.8 mIU/mL.  Consistently elevated FSH levels (above 30 mIU/mL for a prolonged period) are often used, in conjunction with a lack of menstruation for 12 months and other symptoms, to confirm menopause.

 However, a woman’s FSH level is in a constant state of flux throughout her menstrual cycle. According to the National Institute of Health’s National Library of Medicine, this level will not stabilize for 3-6 years post-menopause. 

 So, the overriding question for many women is: How do we know we are in menopause?

 It is the cessation of the period for 12 consecutive months. So, until you have hit that point, blood tests will be variable and are not a reliable diagnostic tool.

 Kelly Rigo is the creative force behind Menopause Evolution.