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.

Outlines

00:00

🚺 Menstrual Cycle and Amenorrhea

This paragraph discusses the menstrual cycle and the conditions of amenorrhea. Menstruation is typically absent before puberty, during pregnancy and lactation, and after menopause. Primary amenorrhea refers to the absence of menstruation by age 16, while secondary amenorrhea is the sudden cessation in someone who has previously menstruated. The menstrual cycle is regulated by the hypothalamus and pituitary gland, which control the secretion of hormones necessary for ovulation and the uterine cycle. The paragraph also explains the phases of the menstrual cycle, including the follicular phase, menstrual phase, proliferative phase, and luteal phase. It further delves into the causes of primary amenorrhea, such as Turner syndrome, Müllerian agenesis, androgen insensitivity syndrome, and endocrine disorders like Coleman syndrome.

05:01

🤰 Causes of Secondary Amenorrhea

The second paragraph focuses on secondary amenorrhea, defined as the absence of menstrual bleeding for at least three cycles or six months in someone who previously had regular cycles. It outlines the various causes, including pregnancy, functional hypothalamic amenorrhea due to factors like weight loss, nutritional deficiencies, and stress, polycystic ovary syndrome (PCOS), pituitary gland issues like hyperprolactinemia, hypothyroidism, premature ovarian failure, and Asherman syndrome. Each cause is briefly explained, detailing how it disrupts the normal menstrual cycle and the hormonal imbalances that result.

10:02

🩺 Diagnosis and Treatment of Amenorrhea

The final paragraph discusses the diagnosis and treatment of amenorrhea. It begins by describing the diagnostic process, which includes ruling out pregnancy and testing serum levels of various hormones, as well as karyotyping for genetic disorders. Diagnostic tools such as ultrasound and hysteroscopy are also mentioned. The paragraph then outlines potential treatments based on the underlying cause, including hormone replacement therapy, dopamine agonists for prolactinomas, surgery for intrauterine adhesions, and psychotherapy for stress-related amenorrhea. The summary concludes with a recap of the causes of both primary and secondary amenorrhea and the diagnostic methods used to identify them.

Keywords

💡Amenorrhea

Amenorrhea refers to the absence of menstruation in females of reproductive age. It can occur naturally before puberty, during pregnancy, lactation, or after menopause. The video discusses two types: primary amenorrhea (when menstruation never begins) and secondary amenorrhea (when menstruation stops after having previously occurred). This concept is central to the video’s theme of understanding various menstrual disorders.

💡Primary Amenorrhea

Primary amenorrhea is when a female has not had her first menstruation by age 16 despite normal growth or by age 13 without signs of puberty. The video attributes causes like Turner syndrome and Müllerian agenesis, which highlight genetic or developmental issues preventing the onset of menstruation. This type of amenorrhea emphasizes the role of genetics and reproductive system development in menstruation.

💡Secondary Amenorrhea

Secondary amenorrhea refers to the cessation of menstruation for at least three normal cycles in a previously menstruating female. The video mentions various causes such as pregnancy, functional hypothalamic amenorrhea, and conditions like polycystic ovary syndrome (PCOS). Understanding this concept is essential for recognizing disruptions in the menstrual cycle due to external or internal factors.

💡Hypothalamus

The hypothalamus is a region in the brain that regulates the release of hormones controlling the menstrual cycle. It secretes gonadotropin-releasing hormone (GnRH), which influences the pituitary gland to release hormones necessary for follicular development and ovulation. The video highlights how disruptions in hypothalamic function, such as stress or weight loss, can lead to conditions like hypothalamic amenorrhea.

💡Follicle-Stimulating Hormone (FSH)

FSH is a hormone released by the pituitary gland that stimulates the growth of ovarian follicles in the first phase of the menstrual cycle. It plays a critical role in follicular development and ovulation. The video explains how changes in FSH levels, such as inhibition by estrogen, impact menstrual cycle regularity and disorders like PCOS.

💡Luteinizing Hormone (LH)

LH is another hormone released by the pituitary gland that triggers ovulation and promotes the formation of the corpus luteum in the ovaries. In the video, LH is discussed in the context of both normal menstrual function and disorders like PCOS, where an imbalance in LH and FSH disrupts ovulation and can lead to secondary amenorrhea.

💡Turner Syndrome

Turner syndrome is a genetic condition where one X chromosome is partially or entirely missing, leading to primary amenorrhea. The video explains that individuals with Turner syndrome have underdeveloped ovaries (streak gonads) that fail to produce necessary hormones, resulting in the absence of menstruation. This condition exemplifies a common genetic cause of primary amenorrhea.

💡Müllerian Agenesis

Müllerian agenesis, also known as Mayer-Rokitansky-Küster-Hauser syndrome, is a developmental disorder where the Müllerian ducts fail to form, resulting in the absence of the uterus, cervix, and upper vagina. The video discusses how this condition leads to primary amenorrhea, as the absence of these reproductive structures prevents menstruation, despite normal ovarian function.

💡Polycystic Ovary Syndrome (PCOS)

PCOS is a hormonal disorder characterized by an imbalance between LH and FSH, leading to irregular ovulation and menstrual cycles. The video explains how this condition causes secondary amenorrhea due to elevated LH levels, which inhibit regular ovulation. PCOS also causes symptoms like hirsutism due to excessive androgen production.

💡Prolactinoma

A prolactinoma is a benign tumor of the pituitary gland that causes excessive secretion of prolactin, leading to hyperprolactinemia. The video mentions that this condition inhibits GnRH production, disrupting ovulation and causing secondary amenorrhea. Prolactinomas are a structural cause of hormonal imbalance affecting menstruation.

Highlights

Amenorrhea refers to the absence of menstruation, which can be normal before puberty, during pregnancy, lactation, and after menopause.

Primary amenorrhea occurs when menstruation hasn't started by age 16 despite normal growth or by age 13 with no signs of puberty.

Secondary amenorrhea is defined as the absence of menstruation for at least three cycles in someone who previously had regular periods.

The hypothalamus and pituitary gland control menstruation through the secretion of hormones like GnRH, FSH, and LH.

Turner syndrome, where one X chromosome is missing or partially absent, is the most common cause of primary amenorrhea.

Mullerian agenesis is another cause of primary amenorrhea, where the uterus and part of the vagina fail to develop, but ovaries are functional.

Androgen insensitivity syndrome can also cause primary amenorrhea; individuals have XY chromosomes but lack functional androgen receptors.

Functional hypothalamic amenorrhea, a common cause of secondary amenorrhea, can be triggered by weight loss, stress, or excessive exercise.

Polycystic ovary syndrome (PCOS) is linked to secondary amenorrhea due to hormonal imbalances between LH and FSH.

Hyperprolactinemia, often caused by a benign pituitary tumor, is another contributor to secondary amenorrhea by suppressing GnRH.

Premature ovarian failure can result in early menopause and secondary amenorrhea due to accelerated depletion of ovarian follicles.

Asherman syndrome, caused by scar tissue in the uterus, is a structural reason for secondary amenorrhea, often following uterine procedures.

The most common symptom of both primary and secondary amenorrhea is the absence of menstruation, with other symptoms varying by cause.

Diagnosis of amenorrhea includes ruling out pregnancy, hormone level assessments, and imaging techniques like ultrasound for structural issues.

Treatment for amenorrhea depends on the underlying cause, including hormone therapy, surgery, dopamine agonists for prolactinomas, and psychotherapy.

Transcripts

amenorrhea means no menstruation it's

normally before puberty during pregnancy

and lactation and after menopause

sometimes though menstruation either

never starts which is called primary

amenorrhea or suddenly stops in a person

who's previously menstruating which is

called secondary amenorrhea

now menstruation and the menstrual cycle

as a whole are controlled by the

hypothalamus and the pituitary gland all

the way up in the brain

the hypothalamus secretes gonadotropin

releasing hormone or gnrh which makes

the nearby anterior pituitary gland

release follicle stimulating hormone or

fsh and luteinizing hormone or lh

in the first two weeks of an average

28-day cycle the ovaries go through the

follicular phase

meaning that out of the many follicles

scattered throughout the ovaries a

couple of them enter a race to become

the dominant follicle that will be

released at ovulation

all the developing follicles secrete

loads of estrogen which negatively

inhibits pituitary fsh

in the meantime the uterus goes through

two phases the menstrual and the

proliferative phase

during the menstrual phase the

functional layer of the endometrium is

shed and eliminated through the vagina

leading to menstruation which lasts an

average of five days

it's followed by the proliferative phase

during which the rising levels of

ovarian estrogen make the functional

layer of the endometrium thicken and

sprout endometrial glands

additionally spiral arteries emerge to

nourish the growing functional

endometrium

after ovulation the ovaries enter the

luteal phase which lasts for the two

weeks following ovulation

during the luteal phase the remnant of

the ovarian follicle called the corpus

luteum makes progesterone which

negatively inhibits pituitary lh

progesterone makes the endometrium go

through the secretory phase during which

it thickens some more and spiral

arteries continue to grow

if the egg is not fertilized by a sperm

estrogen and progesterone levels slowly

decrease

when progesterone reaches its lowest

level the spiral arteries collapse and

the functional layer dies off and is

eliminated through menstruation which

marks the beginning of a new menstrual

cycle

okay now coming back to amenorrhea

primary amenorrhea is when a female

hasn't had her first menstruation called

menarche by age 16 despite normal growth

and having started puberty

primary amenorrhea is also suspected

when a female hasn't had menarche by age

13 and doesn't show signs of puberty

which include developing secondary

sexual characteristics like breasts

the most common cause of primary

amenorrhea is turner syndrome where one

x chromosome is either completely or

partially absent

the most common karyotype is 45x

which means the person has 45

chromosomes of which only one is an x

chromosome

with turner syndrome the ovaries are

replaced by street gonads or

functionless fibrous tissue

this happens because the missing x

chromosome leads to accelerated ovarian

follicle depletion so that by two years

old none are left essentially causing

menopause before menarche

no ovarian follicles also means no

estrogen and progesterone which leads to

high levels of fsh and lh

the second most common cause of primary

amenorrhea is mullerian a genesis which

is also called meijer rokitansky kester

hauser syndrome

in this case the muellerian duct system

doesn't develop properly in a

biologically female fetus

the mullerian duct system is responsible

for the development of the uterus cervix

and upper two thirds of the vagina so

these organs may be absent or

rudimentary and obstructed which

explains the absence of menses

but the ovaries develop normally in

these individuals and the ovarian

follicles make normal amounts of

estrogen and progesterone so there are

normal levels of fsh and lh

a rare cause of primary amenorrhea is

androgen insensitivity syndrome

in this case the individual is

biologically male which means they have

a 46 xy karyotype but their androgen

receptors don't respond to testosterone

so they don't have a uterus fallopian

tubes or ovaries which explains the

absence of menses but they have

testicles which are usually in the

abdomen or inguinal canal and they make

up the normal amount of testosterone for

a biologically male individual so fsh

and lh levels are normal

some of that testosterone gets converted

into estrogen so these people have

female external genitalia and female

secondary sex characteristics

finally endocrine disorders can also

cause primary amenorrhea

these include coleman syndrome where

gnrh producing neurons fail to migrate

from the nose region to the hypothalamus

during fetal development this causes low

levels of gnrh fsh and lh

and as a consequence low estrogen so

puberty either never starts or is

incomplete

okay now let's switch gears and look at

causes of secondary amenorrhea which is

defined as no menstrual bleeding for at

least three normal menstrual cycles in a

female who previously had regular cycles

or for six months for females who used

to have irregular cycles

there are many causes of secondary

amenorrhea and when they occur before

menarche all of these can also cause

primary amenorrhea

the most common cause of secondary

amenorrhea is pregnancy

next there's functional hypothalamic

amenorrhea which is when there's a

decrease in gnrh secretion leading to

low levels of lh fsh and estrogen

often this is due to weight loss from

anorexia nutritional deficiencies like

excessively low fat consumption

prolonged periods of strenuous exercise

or severe physical or emotional stress

another condition that affects the

hypothalamic pituitary ovarian axis and

can be responsible for secondary

amenorrhea is polycystic ovary syndrome

now it's not clear exactly what causes

pcos but there seems to be an imbalance

between lh and fsh levels

specifically ovulation doesn't occur so

progesterone levels don't rise enough to

inhibit lh production

this leads to an increase in the

production of lh compared to fsh

so there's an elevated lh to fsh ratio

additionally because there's

post-ovulatory rise and fall in

progesterone there's no menstruation

issues with the pituitary gland can also

cause secondary amenorrhea one cause is

hyperprolactinemia or excessive

prolactin secretion by pituitary

lactotroph cells

which is frequently seen with a benign

pituitary tumor called a prolactinoma

high prolactin levels inhibit

hypothalamic gnrh production

which inhibits ovulation and

menstruation

interestingly

hypothyroidism a condition where there's

low levels of thyroid hormones can also

cause amenorrhea

this is because low thyroid hormone

levels tell the hypothalamus to release

more thyrotropin releasing hormone or

trh and tell the pituitary to release

more thyroid stimulating hormone or tsh

when this happens trh also stimulates

prolactin release so hyperprolactinemia

and amenorrhea occur

now sometimes secondary amenorrhea can

occur because of premature ovarian

failure which is when the ovarian

follicles undergo accelerated atresia

and get depleted before the age of 40

resulting in early menopause

this leads to low serum estrogen and

high fsh and lh

finally a structural cause of secondary

amenorrhea is intrauterine adhesions or

asherman syndrome which is when there's

scar tissue inside the uterine cavity

typically in a female that's undergone

uterine instrumentation in the past

amenorrhea can occur because there's so

much scar tissue that there's no

functional endometrium left or because

the presence of scar tissue makes the

endometrium refractory to hormonal

stimulation

the one symptom of both primary and

secondary amenorrhea is well the absence

of menstruation

additional symptoms depend on the cause

individuals with turner syndrome have a

short stature

absent secondary sex characteristics and

a wide or webbed neck

eulerian a genesis might cause

dysperunia or painful sexual intercourse

and infertility

with androgen insensitivity syndrome

individuals typically have sparse body

hair and little to no pubertal acne

with coleman syndrome there may be

anosmia or absent sense of smell

because the neurons responsible for

olfaction are closely related to the

ones that release gnrh

with functional hypothalamic amenorrhea

due to anorexia there's significant

weight loss and decreased bone density

which can cause fractures

with polycystic ovary syndrome the

ovarian follicles secrete too much

testosterone causing hirsutism or

excessive hair growth on the chin and

upper lip chest and back

with a prolactinoma there might be

galacteria or abnormal milk production

with premature ovarian failure there may

be additional symptoms like hot flashes

or vaginal dryness

with intrauterine adhesions there could

be infertility

the first step in diagnosing primary or

secondary amenorrhea is to rule out

pregnancy with a pregnancy test

if that's negative diagnosis requires

serum levels of fsh lh

estrogen prolactin

tsh and testosterone

a karyotype can be done for turner

syndrome and androgen insensitivity

syndrome

an ultrasound can show if there are

structural issues with the vagina and

the uterus which suggests mullerian

agenesis or if there's no uterus and

intra-abdominal testicles are found

that suggests androgen insensitivity

syndrome

intrauterine adhesions can be visualized

through hysteroscopy

treatment depends on the underlying

condition

hormone replacement therapy like

combined oral contraceptives can be

useful for individuals with turner

syndrome polycystic ovarian syndrome or

premature ovarian failure

for a prolactinoma dopamine agonists

like cabergoline can be used because

they inhibit prolactin secretion just

like dopamine naturally would and they

shrink the adenoma

surgery can be used to remove

intrauterine adhesions and to help

correct some of the structural issues in

mularian agenesis

in some cases psychotherapy can also be

useful as well as treatment for the

related fertility issues

alright as a quick recap amenorrhea is

the abnormal absence of menstruation in

females of reproductive age it can be

primary in which menstruation never

started or secondary in which case

regular menstruation has stopped in a

female who is previously menstruating

causes of primary amenorrhea include

turner syndrome muellerian agenesis

androgen insensitivity syndrome and

endocrine disorders like coleman

syndrome

causes of secondary amenorrhea can also

cause primary amenorrhea and they

include functional hypothalamic

amenorrhea polycystic ovary syndrome

hyperprolactinemia

premature ovarian failure and asherman

syndrome

other associated symptoms serum fsh lh

estrogen and testosterone as well as an

ultrasound or a karyotype can be used to

identify the underlying condition