The Menstrual Cycle and Menstrual Disorders - Week 2

Vocabulary flashcards covering hormones, cycles, disorders, diagnostic terms, and common pathologies from the lecture notes.

Corpus Luteum

The yellow body left on the ovary after ovulation; secretes progesterone.

Progesterone

Hormone produced by the corpus luteum that prepares the endometrium for potential pregnancy and provides negative feedback on the HPO axis.

Estradiol (Reproductive years form of Estrogen)

Primary ovarian estrogen produced by granulosa cells; promotes endometrial growth and regulates the cycle; high levels provide feedback on FSH/LH.

GnRH (Gonadotropin-releasing hormone)

Hormone from the hypothalamus that stimulates the pituitary to release FSH and LH.

FSH (Follicle-stimulating hormone)

Hormone that stimulates follicle development in the ovary and is secreted in response to GnRH.

LH (Luteinizing hormone)

Hormone that triggers ovulation and stimulates the corpus luteum to secrete progesterone.

Granulosa cells

Specialized cells in the ovarian follicles that support the developing egg and secrete hormones essential for the menstrual cycle - specifically, they convert androgens into estradiol.

Follicle

Developing ovarian egg-containing structure that grows under FSH influence and secretes estrogen.

Ovulation

Release of the ovum from the mature follicle, typically around midcycle (~CD14), followed by corpus luteum formation. This process is triggered by a surge in luteinizing hormone (LH) and is crucial for fertility. Estrogen peaks before and Progesterone peaks afterwards.

Ovarian cycle

Cycle of follicular development, ovulation, and corpus luteum formation and regression.

Menstrual cycle

Combined ovarian and uterine cycle, including menstrual, proliferative, and secretory phases.

Follicular or Proliferative phase

Estrogen-dominant phase of the ovarian/uterine cycle which begins on CD1 and lasts until ovulation. During this phase, levels of follicle-stimulating hormone (FSH) increase, stimulating ovarian follicles to grow. Rising Estrogen levels promote endometrial growth.

Luteal or Secretory phase

Progesterone-dominant phase of the Ovarian cycle, which comes after ovulation (~CD14) when the corpus luteum secretes progesterone, preparing the endometrium for implantation.

Menstrual phase

Phase of shedding of the endometrium if pregnancy does not occur; bleeding occurs.

down-regulation of HPO hormone production - High estradiol/progesterone from ovaries will signal hypothalamus & pituitary to suppress GnRH, FSH, and LH

Negative feedback (HPO axis)

Positive feedback (HPO axis)

Up-regulation of HPO hormone production -

High estradiol just before ovulation => surge in LH => ovulation.

Gonadotropin-Releasing Hormone (GnRH)

Hormone from the hypothalamus that stimulates pituitary FSH/LH release.

Ovary

Gonad that produces eggs (follicles) and secretes estrogen and progesterone.

Estrogen (Estradiol)

Primary ovarian estrogen; drives follicular growth and endometrial proliferation.

Amenorrhea

Absence of menses; can be Primary (no periods by age threshold) or Secondary (cessation after menarche).

Primary Amenorrhea

Absence of menses by age 16 with normal secondary sexual characteristics or by age 14 without puberty.

Secondary Amenorrhea

Absence of menses for 3+ months in someone who has previously menstruated.

Gonadotrophic amenorrhea

Amenorrhea due to pituitary or hypothalamic failure with low FSH/LH.

Hypergonadotrophic hypogonadism

High FSH with low estrogen due to ovarian failure (e.g., menopause, Premature Ovarian Insufficiency).

gonads underperform → low sex hormones → pituitary overcompensates with high LH/FSH.

It can be primary (problem in the gonads themselves, e.g., Turner syndrome, Klinefelter syndrome) or acquired (due to infection, radiation, or trauma).

Hypogonadotrophic hypogonadism

Low FSH/LH with low estrogen due to hypothalamic/pituitary dysfunction (e.g., FHA).

ovaries are fully capable, but the signaling from the hypothalamus or pituitary is insufficient, leading to low sex hormone production in ovaries.

Common causes include Kallmann syndrome, pituitary tumors, or chronic systemic illness.

Normogonadotrophic anovulation

Normal FSH/LH but anovulatory cycles, often with low progesterone.

In short: normal HPO signaling, but the ovaries fail to ovulate.

often due to subtle hormonal imbalances or follicular dysfunction.

A common example is polycystic ovary syndrome (PCOS)

Polycystic Ovary Syndrome (PCOS)

Common cause of anovulation with irregular menses and hyperandrogenism; often with normal FSH and high LH (LH:FSH ~3:1) and polycystic ovaries.

Functional hypothalamic amenorrhea (FHA)

Hypothalamic suppression of GnRH due to weight loss, stress, or exercise; low estrogen and potential osteopenia. It results in the absence of menstruation and can impact bone health and fertility.

Prolactin

Pituitary hormone; high levels suppress GnRH and can cause amenorrhea; normal <25 ng/mL.

Prolactinoma

Pituitary adenoma that produces prolactin; causes hypogonadotropic hypogonadism and amenorrhea.

Empty Sella Syndrome (ESS)

Pituitary gland shrinks or is flattened; sella turcica filled with CSF; can be associated with hyperprolactinemia.

Turner Syndrome (45,XO)

Genetic condition with partial/total X chromosome loss; associated with short stature and hypergonadotrophic hypogonadism.

Müllerian Agenesis

Embryologic failure to develop the uterus and/or vagina; primary amenorrhea with normal secondary sex characteristics.

Androgen Insensitivity Syndrome (AIS)

XY individuals with resistance to androgens; complete AIS has female external phenotype but no uterus.

Kallmann Syndrome

Hypogonadotropic hypogonadism with anosmia; delayed or absent puberty due to GnRH deficiency.

Outflow tract obstructions

Obstructions such as imperforate hymen or transverse vaginal septum causing primary amenorrhea.

Endometrial Hyperplasia

Thickening of the endometrium often from unopposed estrogen; risk of cancer; diagnosed by biopsy.

Endometrial cancer

Cancer of the uterine lining; commonly presents with abnormal vaginal bleeding.

Dysfunctional Uterine Bleeding (DUB) / AUB

Abnormal uterine bleeding not due to structural disease; diagnosis of exclusion; PALM-COEIN used for classification.

PALM-COEIN

Classification of causes of heavy menstrual bleeding: Structural (Polyp, Adenomyosis, Leiomyoma, Malignancy) and Non-structural (Coagulopathy, Ovulatory, Endometrial, Iatrogenic, Not classified).

Menorrhagia

Heavy menstrual bleeding: >7 days or >80 mL blood loss with clots, regular cycles.

Metrorrhagia

Bleeding at irregular, frequent intervals, often between periods.

Menometrorrhagia

Heavy bleeding with irregular timing.

Oligomenorrhea

Infrequent menses with cycle length >35 days.

Polymenorrhea

Frequent menses with cycle length <21 days.

Bleeding patterns: ovulatory involves regular ovulation; anovulatory lacks ovulation, leading to unopposed estrogen and irregular bleeding.

Ovulatory vs Anovulatory bleeding

Basal Body Temperature (BBT)

Daily measurement of Body Temperature upon waking; which is tracked to note a distinct rise in temp after ovulation indicating luteal phase; used to track ovulation w/in cycle.

Luteal progesterone test

Measuring progesterone in luteal phase to confirm ovulation; typically >2–25 ng/mL indicates ovulation.

Progestin challenge test

Withdrawal bleed after progestin challenge suggests estrogen sufficiency and outflow tract integrity.

Endometrial biopsy/Hysteroscopy/TVUS/SIS

Imaging and sampling tools to evaluate endometrial pathology and intrauterine abnormalities.

Mirena (levonorgestrel IUD)

Intrauterine device delivering progestin to regulate bleeding and treat menorrhagia.

Tranexamic acid (Lysteda)

Antifibrinolytic medication used to reduce menorrhagia.

Ectopic pregnancy

Pregnancy implanted outside the uterus; presents with pain and bleeding in early pregnancy.

Hydatidiform mole (molar pregnancy)

Molar pregnancy with abnormal trophoblastic tissue; causes vaginal bleeding and pregnancy complications.

Placenta previa

Placenta partially or completely covers the cervix, causing bleeding.

Spontaneous abortion (SAB)

Miscarriage; loss of pregnancy before 20 weeks gestation.

Sheehan’s syndrome

Postpartum pituitary necrosis from severe bleeding; risk of adrenal crisis and hypopituitarism.