When to check estrogen and progesterone levels?

From the Guidelines

Estrogen and progesterone levels should be checked during specific phases of the menstrual cycle, typically on day 3 of the cycle for baseline levels and during the mid-luteal phase to assess progesterone production, as indicated by the study published in the Journal of Neurology, Neurosurgery and Psychiatry 1. When evaluating hormone levels, it's essential to consider the timing of the menstrual cycle.

• Estrogen levels can be checked on day 3 of the cycle for baseline levels.
• Progesterone levels should be measured during the mid-luteal phase, according to the menstrual cycle, as low levels may indicate anovulation, a common cause of which is polycystic ovary syndrome (PCOS) 1. These hormones may also be tested when evaluating fertility issues, menstrual irregularities, symptoms of menopause, or suspected hormonal imbalances.
• For fertility assessment, estradiol (a form of estrogen) is often checked on day 3, while progesterone is best measured about 7 days after ovulation to confirm that ovulation has occurred.
• In cases of hormone replacement therapy, levels may be monitored to ensure appropriate dosing. The study highlights the importance of considering PCOS, a form of hyperandrogenic chronic anovulation, which affects approximately 4–6% of women in the general population and has a higher prevalence in patients with temporal lobe epilepsy 1.
• PCOS is characterized by hypersecretion of luteinising hormone, ovarian theca stromal cell hyperactivity, and hypofunction of the follicle stimulating hormone (FSH)–granulosa cell axis, resulting in hyperandrogenism, hirsutism, follicular arrest, and ovarian acyclicity.
• The pathogenesis of PCOS involves the acceleration of pulsatile gonadotropin releasing hormone (GnRH) secretion, insulin resistance, hyperinsulinaemia, and downstream metabolic dysregulation. It's crucial to note that the timing of hormone testing is vital because these hormones naturally fluctuate throughout the menstrual cycle - estrogen peaks just before ovulation while progesterone rises after ovulation and remains elevated until menstruation if pregnancy doesn't occur, as discussed in the context of reproductive endocrine disorders in women with epilepsy 1.

From the Research

Estrogen and Progesterone Levels

To determine when to check estrogen and progesterone levels, it's essential to consider the context of the patient's condition and the purpose of the test.

• In the context of ovulation induction, estrogen and progesterone levels can be checked during a clomiphene citrate treatment cycle to monitor the ovarian response and follicular maturation 2.
• Estrogen levels can be checked 8-10 days before the luteinizing hormone surge, and progesterone levels can be checked from the day of the surge to the end of the cycle 3.
• In postmenopausal women, estrogen and progesterone levels can be checked during hormone replacement therapy to monitor the endometrial response and prevent endometrial stimulation 4.

Timing of Hormone Level Checks

The timing of hormone level checks depends on the specific treatment or condition being monitored.

• During clomiphene citrate treatment, hormone levels can be checked daily or every other day to monitor the ovarian response and follicular maturation 2.
• In postmenopausal women, hormone levels can be checked after the first estrogen treatment and after the first and third clomiphene periods to monitor the endometrial response 4.
• In women with heavy menstrual bleeding, hormone levels may not be directly relevant to the diagnosis or treatment, but may be checked as part of a comprehensive evaluation 5.

Relevant Studies

Several studies have investigated the role of estrogen and progesterone in various conditions, including ovulation induction, postmenopausal hormone replacement therapy, and heavy menstrual bleeding.

• A study published in 1991 found that clomiphene citrate treatment increased estrogen and progesterone levels in women with ovulation induction 3.
• A study published in 2017 discussed the management of heavy menstrual bleeding, but did not specifically address the role of estrogen and progesterone levels in this condition 5.
• A study published in 1981 found that postmenopausal hormone replacement therapy with estrogen periodically supplemented with antiestrogen (clomiphene) relieved climacteric symptoms without endometrial stimulation 4.
• A study published in 2005 discussed ovulation induction and the use of clomiphene citrate as a first-line treatment for anovulatory infertility 6.
• A study published in 1977 measured plasma hormone levels in women undergoing clomiphene citrate therapy and found that estrogen and progesterone levels rose during treatment 2.