Female Reproduction: Physiology and Contraceptives

A set of flashcards covering vocabulary related to female reproductive physiology and contraceptive methods, designed to aid in exam preparation.

GnRH

Gonadotropin-releasing hormone; regulates reproductive functions by stimulating the pituitary gland to release gonadotropins.

FSH

Follicle-stimulating hormone; a gonadotropin involved in the development of ovarian follicles in females.

LH

Luteinizing hormone; a gonadotropin that triggers ovulation and stimulates the corpus luteum to produce progesterone.

Menstrual Cycle

A monthly cycle in females characterized by the regulation of hormonal activity, ovulation, and potential menstruation.

Oögenium

The female germ cell that undergoes mitosis to eventually form oocytes.

Corpus Luteum

A hormone-secreting structure that develops in an ovary after an ovum has been discharged.

Progestogen-only Pill (POP)

A contraceptive that contains only progestogens, effective without estrogen.

Combined Oral Contraceptive (COC)

A contraceptive pill that combines estrogen and progestin to prevent ovulation.

Ovulation

The release of an egg from the ovary, typically occurring in the middle of the menstrual cycle.

Anti-Müllerian Hormone (AMH)

A hormone involved in the regression of the Müllerian duct, playing a critical role in male sexual differentiation.

Gametogenesis

The process of forming gametes, including oocytes in females and sperm in males.

Follicular Phase

The first phase of the ovarian cycle, where follicles mature before ovulation.

Luteal Phase

The second phase of the ovarian cycle, following ovulation, characterized by the presence of the corpus luteum.

Hormonal Contraception

Methods of birth control that use hormones to prevent ovulation or alter the menstrual cycle.

Inhibin

A hormone produced by the gonads that inhibits FSH production, helping regulate reproductive functions.

SRY Protein

A protein that determines male sex development by initiating the formation of testis.

Endometrial Layer

The inner lining of the uterus that thickens in preparation for implantation and is shed during menstruation.

Cervical Mucus

The fluid produced by glands in the cervix that changes in consistency during the menstrual cycle, influencing sperm passage.

"What’s the “HPG axis” in female reproduction?"

"Hypothalamus releases GnRH → anterior pituitary releases FSH + LH → ovaries produce sex hormones and regulate follicle/ovulation."

"What triggers GnRH release during the cycle?"

"Falling (low) ovarian hormone levels provide the stimulus that increases GnRH; leading to FSH/LH release."

"What are the two phases of the ovarian cycle?"

"Follicular phase (pre-ovulation) and luteal phase (post-ovulation)."

"What is the “hallmark” event of the ovarian cycle?"

"Ovulation (release of the egg)."

"Which cells are in the ovarian follicle?"

"Theca cells + granulosa cells."

"What does LH do in the follicle?"

"LH stimulates theca cells → androgen synthesis."

"What does FSH do in the follicle?"

"FSH stimulates granulosa cells → aromatase expression."

"What does aromatase do?"

"Converts androgens (e.g.; testosterone) into oestrogen (estradiol) in granulosa cells."

"What happens after ovulation to the leftover follicle?"

"It becomes the corpus luteum."

"What does the corpus luteum produce?"

"Mainly progesterone + also oestrogen (plus inhibin mentioned)."

"What causes menstruation/end of cycle hormonally?"

"Corpus luteum degenerates → progesterone/oestrogen fall → endometrium sheds and GnRH/FSH rises to start next cycle."

"What happens to the endometrium across the uterine cycle?"

"It builds up (proliferates) to prepare for implantation; then sheds if no pregnancy."

"When are primary oocytes formed?"

"In embryonic life; they proliferate via mitosis; enter meiosis I; and then arrest."

"What is the key point about egg number at birth?"

"Females are born with a finite set number of primary oocytes."

"What resumes at puberty?"

"Meiosis I resumes in selected oocytes → secondary oocyte + first polar body."

"When does meiosis II complete?"

"Only if fertilisation occurs (otherwise the secondary oocyte degenerates)."

"Main mechanism of combined hormonal contraception (CHC)?"

"Inhibits ovulation by suppressing FSH/LH (negative feedback)."

"How does CHC “trick” the body (as explained)?"

"Synthetic oestrogen + progestogen maintain hormone levels → interrupt the “low hormone” trigger → no LH/FSH surge → no ovulation."

"Role of oestrogen in CHC (per lecture emphasis)?"

"Suppresses gonadotropins (FSH/LH); preventing the ovulatory surge."

"Role of progestogen in CHC?"

"Thickens cervical mucus; alters tubal motility; and keeps endometrium thin → reduces implantation likelihood + sperm penetration."

"Main mechanism of progestogen-only pill (POP)?"

"Mainly thickens cervical mucus + keeps endometrium thin; ovulation inhibition occurs in a minority (~25% mentioned; depending on progestogen)."

"What does “proliferative effects of oestrogen” mean clinically?"

"Oestrogen builds up the endometrium; progestogen is needed to oppose excess thickening."

"Why compare “typical” vs “perfect” use?"

"Many methods are user-dependent; missed doses/errors increase pregnancy rates."

"Which methods were highlighted as most effective in the slide?"

"Long-acting methods like progestogen-only injectables and levonorgestrel intrauterine system/device (IUD terminology noted)."

"Approximate failure rates with perfect use (from slide talk)?"

"LARC highlighted ~0.2% unintended pregnancy in first year; CHC/POP ~0.3% with perfect use."

"Why are pills/patch/ring less effective with typical use?"

"Because effectiveness relies on consistent; correct use (adherence)."

"What are the three UK forms of combined hormonal contraception?"

"Combined pill; transdermal patch; vaginal ring."

"What is “monophasic” combined pill?"

"Same oestrogen/progestogen dose in each active pill through the pack."

"What is “multiphasic” combined pill?"

"Hormone doses vary across the cycle (less commonly first line; example mentioned: Qlaira)."

"What is a 21/7 regimen?"

"21 active pills then 7-day hormone-free interval (withdrawal bleed)."

"What is a “withdrawal bleed”?"

"Bleeding caused by hormone drop during the break; not a true physiological period."

"What is an “everyday (ED) pill” pack?"

"28 pills: typically 21 active + 7 placebo, so the patient takes a pill daily

"Why use tailored/continuous regimens (back-to-back packs)?"

"Can reduce escape ovulation risk during hormone-free interval and may reduce side effects from hormone fluctuations; breakthrough bleeding can occur."

"What’s a potential drawback of continuous CHC use?"

"Breakthrough bleeding (usually short-lived)."

"Key pre-CHC checks mentioned?"

"Exclude pregnancy; check BP (aim

"What is UKMEC used for?"

"Safety eligibility guidance for contraceptive methods in different medical conditions (not primarily effectiveness)."

"UKMEC Category 1 means?"

"No restriction for use."

"UKMEC Category 2 means?"

"Benefits generally outweigh risks."

"UKMEC Category 3 means?"

"Risks generally outweigh benefits; specialist advice usually needed; consider only if other options unsuitable."

"UKMEC Category 4 means?"

"Unacceptable health risk; do not use."

"Major caution highlighted for CHC?"

"Increased clot risk (VTE)."

"Non-contraceptive benefits mentioned for CHC?"

"Less painful/heavy periods; reduced PMS; less symptomatic fibroids; improved functional ovarian cyst symptoms; less benign breast disease; reduced risk of ovarian + endometrial cancer; reduced PID; also mentioned colorectal cancer risk reduction and post-surgery endometriosis recurrence reduction."

"What determines development of female internal reproductive organs in the fetus?"

"Absence of SRY protein; testosterone; and anti-Müllerian hormone allows Müllerian ducts to develop into uterus; fallopian tubes; cervix; and upper vagina."

"What happens to the Wolffian duct in female development?"

"It regresses due to absence of testosterone."

"Why is female reproduction considered more complex than male?"

"It involves cyclical hormone changes; follicle maturation; ovulation; and uterine preparation rather than continuous gamete production."

"What are the two main functions of the ovary?"

"Production of female sex hormones and production of female germ cells (oocytes)."

"What is the role of inhibin in the menstrual cycle?"

"Suppresses FSH release to prevent recruitment of additional follicles."

"What is the effect of sustained high oestrogen levels before ovulation?"

"Switches from negative to positive feedback on the pituitary; triggering the LH surge."

"What causes the LH surge?"

"High circulating oestrogen levels in the late follicular phase."

"What is the primary role of progesterone in the luteal phase?"

"Maintains a secretory endometrium suitable for implantation."

"What happens hormonally when the corpus luteum degenerates?"

"Progesterone and oestrogen levels fall; removing negative feedback and initiating a new cycle."

"What uterine phase corresponds to the luteal phase?"

"Secretory phase."

"What is anti-Müllerian hormone (AMH) produced by in the ovary?"

"Granulosa cells of developing follicles."

"What is the function of AMH in the ovary?"

"Prevents excessive follicle recruitment."

"Why do combined oral contraceptives prevent endometrial hyperplasia?"

"Progestogen opposes the proliferative effects of oestrogen on the endometrium."

"What is the main pharmacological target of oral contraceptives?"

"The hypothalamic–pituitary–ovarian axis."

"Why is ovulation suppression central to contraceptive efficacy?"

"Without ovulation; no egg is available for fertilisation."

"What additional mechanisms (besides ovulation suppression) help prevent pregnancy with CHC?"

"Thickened cervical mucus; reduced tubal motility; and thin endometrium."

"When are progestogen-only pills preferred over combined pills?"

"When oestrogen is contraindicated (e.g. migraine with aura; high VTE risk; breastfeeding)."

"Why must POPs be taken continuously without a pill-free interval?"

"To maintain cervical mucus thickening and endometrial suppression."

"Why is bleeding unpredictable with POPs?"

"Ovulation suppression and endogenous oestrogen levels vary between individuals."

"What is the key counselling point about POP bleeding patterns?"

"Irregular bleeding is common and not usually harmful."

"Why do enzyme-inducing drugs reduce oral contraceptive effectiveness?"

"They increase hepatic metabolism of contraceptive hormones."

"What is the recommended contraceptive strategy with enzyme-inducing drugs?"

"Use non-oral or non-hormonal methods such as injectable or intrauterine contraception."

"Why is lamotrigine clinically significant with CHC use?"

"CHC lowers lamotrigine levels and lamotrigine levels fluctuate during hormone-free intervals."

"What is the purpose of tailored or continuous CHC regimens?"

"To reduce hormone withdrawal effects and avoid escape ovulation."

"Why is the withdrawal bleed not a true menstrual period?"

"It is caused by hormone withdrawal rather than physiological cycling."

"What must be assessed before initiating combined oral contraception?"

"Pregnancy status; blood pressure; BMI;smoking status; medical history; and drug interactions."

"What is the purpose of UKMEC in contraceptive prescribing?"

"To assess safety of contraceptive methods in specific medical conditions."

"What is a key disadvantage of all oral contraceptives?"

"They rely heavily on user adherence."

"What protection do oral contraceptives NOT provide?"

"Protection against sexually transmitted infections."

"What is the pharmacist’s role in oral contraception?"

"Counselling on correct use; side effects; interactions; missed pills; and follow-up."

"When should CHC be stopped immediately?"

"If signs of thromboembolism; severe chest pain; neurological symptoms; jaundice; or prolonged immobilisation occur."

"Why is annual contraceptive review recommended?"

"To reassess safety; adherence; interactions; and suitability of the method."

"What hormones are contained in combined oral contraceptives (COCs)?"

"A synthetic oestrogen (ethinylestradiol) and a synthetic progestogen."

"What is the primary mechanism of action of COCs?"

"Suppression of ovulation."

"How do COCs suppress ovulation at the hormonal level?"

"By suppressing GnRH release; leading to reduced FSH and LH secretion."

"Why does suppression of FSH prevent ovulation?"

"FSH suppression prevents follicular maturation."

"Why does suppression of LH prevent ovulation?"

"LH suppression prevents the LH surge required for ovulation."

"What feedback mechanism do COCs exploit?"

"Negative feedback on the hypothalamic–pituitary–ovarian axis."

"What is the role of oestrogen in COC mechanism?"

"Suppresses FSH release and stabilises cycle control."

"What is the role of progestogen in COC mechanism?"

"Suppresses LH; thickens cervical mucus; and alters the endometrium."