Amenorrhea (Gynecologists' Lecture)

Summary

This video script explains amenorrhea, the absence of menstruation, which can occur before puberty, during pregnancy, or after menopause. It discusses two types: primary amenorrhea, where menstruation never starts, and secondary amenorrhea, where it stops in someone previously menstruating. The script explores causes, including Turner syndrome, Mullerian agenesis, androgen insensitivity syndrome, polycystic ovary syndrome (PCOS), and functional hypothalamic amenorrhea. Diagnostic methods include hormone level testing, karyotyping, and ultrasounds. Treatments vary depending on the cause and can involve hormone therapy, surgery, or medication.

Takeaways

• 🩸 Amenorrhea refers to the absence of menstruation, which is normal before puberty, during pregnancy, lactation, and after menopause, but can also be caused by medical conditions.
• 🧠 Menstruation is regulated by the hypothalamus and pituitary gland, which release hormones like GnRH, FSH, and LH to control ovarian and uterine cycles.
• 🥚 The menstrual cycle consists of the follicular phase (ovarian follicles develop) and luteal phase (corpus luteum produces progesterone). The uterine cycle includes the menstrual phase (shedding of the endometrial lining) and proliferative/secretory phases.
• 👶 Primary amenorrhea occurs when menstruation has not begun by age 16, with Turner syndrome being the most common cause due to the absence or partial absence of an X chromosome.
• 🌱 Mullerian agenesis is another cause of primary amenorrhea where the reproductive organs (uterus, cervix) are absent or underdeveloped, though ovarian function remains normal.
• 👩‍⚕️ Secondary amenorrhea refers to the absence of menstruation for at least three months in someone with previous normal cycles, with pregnancy being the most common cause.
• ⚖️ Functional hypothalamic amenorrhea occurs due to stress, weight loss, or excessive exercise, leading to a decrease in GnRH and estrogen production.
• 🌿 Polycystic ovary syndrome (PCOS) leads to an imbalance in LH and FSH, causing ovulation issues and elevated testosterone levels.
• 🔬 Endocrine disorders like hyperprolactinemia (high prolactin levels) and hypothyroidism can also lead to secondary amenorrhea due to disrupted hormone production.
• 🩺 Treatment of amenorrhea depends on the underlying cause, ranging from hormone replacement therapy to surgery, psychotherapy, or addressing fertility issues.

Q & A

What is amenorrhea and when does it occur naturally?

Amenorrhea is the absence of menstruation. It naturally occurs before puberty, during pregnancy, during lactation, and after menopause.

What are the two types of amenorrhea and how are they different?

The two types of amenorrhea are primary and secondary. Primary amenorrhea occurs when menstruation never starts by a certain age, while secondary amenorrhea happens when menstruation stops in someone who previously had regular periods.

What role do the hypothalamus and pituitary gland play in the menstrual cycle?

The hypothalamus secretes gonadotropin-releasing hormone (GnRH), which triggers the pituitary gland to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH), both of which are essential for regulating the menstrual cycle.

What happens during the follicular phase of the menstrual cycle?

During the follicular phase, several follicles in the ovaries start developing, with one becoming the dominant follicle. These follicles secrete estrogen, which helps regulate FSH levels.

What are the menstrual and proliferative phases in the uterus?

The menstrual phase is when the functional layer of the endometrium is shed, leading to menstruation. The proliferative phase follows, during which estrogen causes the endometrium to thicken and develop glands and spiral arteries.

What causes primary amenorrhea in Turner syndrome?

In Turner syndrome, one X chromosome is missing or partially absent, leading to the early depletion of ovarian follicles. This causes menopause before menarche (the first menstruation).

What are some common causes of secondary amenorrhea?

Common causes of secondary amenorrhea include pregnancy, functional hypothalamic amenorrhea, polycystic ovary syndrome (PCOS), hyperprolactinemia, and premature ovarian failure.

How does polycystic ovary syndrome (PCOS) lead to amenorrhea?

In PCOS, there is an imbalance between LH and FSH levels, causing ovulation not to occur. Without ovulation, progesterone levels don't rise, leading to a lack of menstruation.

How can endocrine disorders like hypothyroidism cause amenorrhea?

Hypothyroidism leads to increased levels of thyrotropin-releasing hormone (TRH), which stimulates prolactin production. Elevated prolactin inhibits GnRH production, causing a disruption in the menstrual cycle.

What are some diagnostic tools used to identify the cause of amenorrhea?

Diagnostic tools include hormone level tests (FSH, LH, estrogen, prolactin, thyroid hormones), karyotyping for genetic disorders, ultrasound for structural issues, and hysteroscopy for detecting intrauterine adhesions.