Progesterone and estradiol – blood test for questions about ovulation, menstrual cycle and hormone levels
By analyzing estradiol and progesterone, you get information about the levels of two central sex hormones at the time of sampling. The hormones vary during the menstrual cycle and are important for, among other things, follicle development, ovulation and development of the uterine lining.
Changed hormone levels can occur together with, for example:
- irregular or absent menstruation.
- changed or prolonged bleeding.
- difficulty determining whether ovulation has occurred.
- hot flashes or sweating.
- sleep problems.
- mood swings.
- decreased sex drive.
Since symptoms can have multiple causes, test results always need to be considered in conjunction with factors such as age, menstrual pattern, day of collection, symptoms, and any use of hormonal medications.
When should the test be taken?
Hormonal levels vary throughout the menstrual cycle, and the time of collection therefore affects how the result can be interpreted. If the purpose is to assess whether ovulation is likely to have occurred, a progesterone test is usually recommended around seven days before the expected period. In a regular 28-day cycle, this often corresponds to around day 21.
For shorter, longer, or irregular cycles, the day of collection needs to be adjusted. A single sample provides a snapshot, and for some problems, additional or repeated sampling may be necessary.
How Estradiol and Progesterone Vary During the Cycle
During the follicular phase, which is the first part of the menstrual cycle, estradiol usually rises before ovulation. After ovulation, the corpus luteum is formed, which produces progesterone. Progesterone levels are normally highest during the mid-luteal phase, while estradiol may show a second, smaller increase.
If pregnancy does not occur, progesterone and estradiol levels fall, which contributes to the start of a new period. Therefore, the result always needs to be interpreted based on the part of the cycle in which the sample was taken.
Hormonal Changes During Perimenopause
During perimenopause, ovulation often becomes more irregular and estradiol and progesterone levels can vary significantly between cycles. These changes can occur along with irregular bleeding, hot flashes, sleep problems, mood swings, and other menopausal symptoms.
A single blood test cannot alone determine perimenopause or explain all symptoms, but the results can provide information that is assessed together with age, menstrual pattern and other complaints.
Interpretation of the results
No static relationship between estradiol and progesterone is calculated. Instead, the results are assessed individually and in relation to the day of sampling, menstrual cycle, age, symptoms and relevant medical information.
When you fill out the health declaration, you indicate where in the cycle the sample was taken as well as any symptoms and hormonal medications. The information gives the doctor a better basis for the written feedback.
Here you can read more about reference values for estrogen (estradiol) and progesterone.
