NLE Reproductive Health & Family Planning — Reproductive Anatomy, Physiology & the Menstrual CycleCheat Sheet

Formula

Sperm survival time = 48–72 hours (up to 5 days in fertile cervical mucus)

Meaning

Duration sperm remain viable in the female reproductive tract

Watch Out

Students often say sperm only last 24 hours — WRONG. They survive 48–72 hours routinely, and up to 5 days in optimal conditions.

When To Use

When calculating fertile window or explaining conception risk

Formula

Spermatogenesis duration = 64–74 days

Meaning

Time from spermatogonium to mature, motile sperm

Watch Out

Common error: confusing spermatogenesis time with sperm transit time through epididymis (~12 days).

When To Use

Explaining why testicular damage (fever, chemotherapy) affects sperm count only weeks later

Formula

Normal sperm concentration ≥15 million/mL (WHO reference)

Meaning

Minimum concentration in a normal ejaculate

Watch Out

Some old standards used 20 million/mL; use ≥15 million/mL for current NLE.

When To Use

Interpreting semen analysis results; defining male factor infertility

Formula

Ejaculate volume = 2–5 mL per ejaculation

Meaning

Normal volume of semen expelled during orgasm

Watch Out

Low volume (<1.5 mL) suggests prostate or seminal vesicle dysfunction; high volume does NOT mean high fertility.

When To Use

Assessing male fertility or sexual dysfunction

Value

33–34°C (1–2°C below core body temperature of ~37°C)

Symbol

T

Quantity

Scrotum temperature

Value

64–74 days

Symbol

t

Quantity

Spermatogenesis duration

Value

≥15 million/mL (WHO reference)

Symbol

[S]

Quantity

Normal sperm concentration

Value

2–5 mL

Symbol

V

Quantity

Ejaculate volume

Value

~12 days

Symbol

t_epi

Quantity

Epididymal transit time

Term

Spermatogenesis

Example

A male with fever in January will have reduced sperm count by March because spermatogenesis is ongoing.

Definition

Continuous production of mature sperm from spermatogonia in seminiferous tubules, driven by FSH and testosterone, taking 64–74 days.

Term

Leydig (interstitial) cells

Example

Damage to Leydig cells from cryptorchidism or heat reduces testosterone production.

Definition

Endocrine cells in the testis that secrete testosterone in response to LH stimulation.

Term

Sertoli cells

Example

FSH stimulates Sertoli cells to produce anti-müllerian hormone (AMH), used to assess ovarian reserve in females.

Definition

Support cells in seminiferous tubules that nurture developing sperm and respond to FSH.

Term

Epididymis

Example

Sperm emerging from seminiferous tubules are immotile; they gain motility in the epididymis over ~12 days.

Definition

Coiled duct on each testis where sperm mature, gain motility, and are stored; site of vasectomy.

Term

Vas (ductus) deferens

Example

Post-vasectomy, sperm are still produced but blocked from ejaculation; stored sperm are reabsorbed.

Definition

Muscular duct carrying mature sperm from epididymis to ejaculatory duct; cut and tied in vasectomy.

Term

Scrotum temperature

Example

Cryptorchidism (undescended testicle) or prolonged fever impairs sperm production due to elevated temperature.

Definition

About 1–2°C below core body temperature (~33–34°C), required for normal spermatogenesis.

Value

~10 cm

Symbol

L_tube

Quantity

Fallopian tube length

Value

3.5–4.5

Symbol

pH_vagina

Quantity

Vaginal pH

Value

~12.5 cm (estimates obstetric conjugate)

Symbol

DC

Quantity

Diagonal conjugate

Value

~11 cm (cannot be measured clinically; estimated from diagonal conjugate)

Symbol

OC

Quantity

Obstetric (true) conjugate

Value

1–2 million

Symbol

N_birth

Quantity

Oocytes at birth

Value

~400,000

Symbol

N_puberty

Quantity

Oocytes at puberty

Value

~400

Symbol

N_lifetime

Quantity

Oocytes ovulated in lifetime

Term

Vulva

Example

Perineal lacerations during childbirth are classified by degree (1°–4°); a 4° laceration extends to the anal sphincter.

Definition

External female genitalia including mons pubis, labia majora/minora, clitoris, vestibule, urethral/vaginal openings, Bartholin's glands, and perineum.

Term

Vagina

Example

Douching destroys vaginal flora and increases risk of bacterial vaginosis and pelvic inflammatory disease (PID).

Definition

Muscular, elastic canal (birth canal, menstrual flow passage, coitus organ); naturally acidic (pH 3.5–4.5) due to Döderlein's lactobacilli.

Term

Endometrium

Example

Hyperplasia of endometrium from unopposed oestrogen (no progesterone) increases endometrial cancer risk.

Definition

Inner mucosal lining of the uterus; site of implantation, menstrual shedding, and response to cyclic hormones.

Term

Myometrium

Example

Uterine atony (failure of myometrium to contract postpartum) causes severe postpartum haemorrhage (PPH).

Definition

Thick smooth muscle layer of the uterus; contracts during labour and compresses spiral arteries to arrest postpartum bleeding.

Term

Fimbriae

Example

Scarring from PID can damage fimbriae, causing tubal infertility and ectopic pregnancy risk.

Definition

Finger-like projections on the distal end of fallopian tube that sweep the ovum into the tube after ovulation.

Term

Ampulla

Example

Fertilisation occurs in the ampulla; if the blastocyst implants in the tube (ectopic pregnancy), it will rupture and haemorrhage.

Definition

Widest, most muscular portion of the fallopian tube (outer third); normal site of fertilisation.

Term

Ovary

Example

A female is born with ~1–2 million oocytes, declining to ~400,000 at puberty; only ~400 will ovulate in a lifetime.

Definition

Paired gonad producing oocytes (eggs) and secreting oestrogen and progesterone; no new oocytes are produced after birth.

Term

Cervix

Example

Cervical incompetence (premature dilation) increases miscarriage risk, especially in 2nd trimester; treated with cervical cerclage.

Definition

Lower portion of uterus extending into vagina; opens slightly during cycle and dilates to 10 cm during labour.

Term

Perineum

Example

A 3rd-degree perineal tear extends into the external anal sphincter; careful repair is needed to prevent faecal incontinence.

Definition

Area between vaginal opening and anus; site of episiotomy or spontaneous lacerations during vaginal delivery.

Value

24–36 hours before ovulation

Symbol

t_LH_surge

Quantity

LH surge duration

Value

~200 pg/mL (17β-oestradiol)

Symbol

[E2]_threshold

Quantity

Oestrogen threshold for LH surge

Value

~14 days (fixed, unless rescued by hCG)

Symbol

t_CL

Quantity

Corpus luteum lifespan

Value

~0.3–0.5°C

Symbol

ΔT_BBT

Quantity

BBT rise after ovulation

Term

GnRH (gonadotropin-releasing hormone)

Example

GnRH agonists (e.g., leuprolide) suppress FSH/LH by downregulating GnRH receptors; used to suppress endometriosis.

Definition

Decapeptide from hypothalamus; released in pulses to stimulate anterior pituitary FSH and LH release.

Term

FSH (follicle-stimulating hormone)

Example

Rising FSH in early follicular phase recruits multiple follicles; only one becomes dominant due to high local oestrogen and FSH receptor expression.

Definition

Gonadotropin from anterior pituitary; stimulates ovarian follicle growth and oestrogen production in females; supports spermatogenesis in males.

Term

LH (luteinizing hormone)

Example

LH surge is the trigger for ovulation; ovulation predictor kits detect urinary LH surge to identify the fertile window.

Definition

Gonadotropin from anterior pituitary; the sharp LH surge (~24–36 hours before ovulation) triggers rupture of mature follicle and ovulation.

Term

Oestrogen (17β-oestradiol, oestrone, oestriol)

Example

Rising oestrogen in late follicular phase exerts positive feedback on LH, triggering the LH surge and ovulation.

Definition

Steroid hormone primarily from granulosa cells of growing follicle; promotes endometrial proliferation, thin cervical mucus (spinnbarkeit), and secondary sex characteristics.

Term

Progesterone

Example

Progesterone withdrawal (corpus luteum regression) triggers menstruation; mifepristone (progesterone antagonist) induces medical abortion.

Definition

Steroid hormone from corpus luteum (and later placenta); makes endometrium secretory, thickens cervical mucus, raises BBT by ~0.3–0.5°C, and maintains early pregnancy.

Term

hCG (human chorionic gonadotropin)

Example

hCG is detected by pregnancy tests (serum β-hCG or urine hCG); rises 48–72 hours after positive test if viable pregnancy.

Definition

Glycoprotein from trophoblast/placenta after implantation; maintains corpus luteum to continue progesterone production until placenta takes over (~10 weeks).

Term

Testosterone

Example

Exogenous testosterone (anabolic steroid abuse) suppresses endogenous FSH/LH, causing infertility and testicular atrophy.

Definition

Androgen from Leydig cells stimulated by LH; drives spermatogenesis and male secondary sex characteristics; small amounts also produced in females (adrenal/ovary).

Formula

Cycle length = Follicular phase + Ovulation + Luteal phase

Meaning

Total cycle duration; average 28 days (range 21–35 days)

Watch Out

The follicular phase VARIES (21–35 days); the luteal phase is FIXED at ~14 days. Cycle variation comes from follicular phase length.

When To Use

Calculating expected ovulation date or assessing cycle abnormalities

Formula

Estimated ovulation date = Cycle length − 14 days

Meaning

Subtract 14 days from cycle length to estimate when ovulation occurred

Watch Out

Many students assume ovulation is always day 14; WRONG. Day 14 is only true for 28-day cycles. Use cycle length − 14.

When To Use

Predicting ovulation in women with irregular cycles; if cycle is 35 days, ovulation is ~day 21 (not day 14)

Formula

Menstrual flow duration = 2–7 days; average blood loss = 30–80 mL

Meaning

Normal parameters for menstruation

Watch Out

Patients often overestimate blood loss; teach them that ~1 fully soaked pad = ~5 mL (so 16 pads ≠ 80 mL; 16 pads = ~80 mL).

When To Use

Assessing dysmenorrhoea or menorrhagia; losses >80 mL or flow >7 days warrant investigation

Value

21–35 days (average 28 days)

Symbol

C_len

Quantity

Normal cycle length

Value

Variable, 10–24+ days (average ~14 days)

Symbol

t_foll

Quantity

Follicular phase length

Value

Fixed, ~14 days (range 12–16 days)

Symbol

t_lut

Quantity

Luteal phase length

Value

2–7 days (average ~4–5 days)

Symbol

t_menses

Quantity

Menstrual flow duration

Value

30–80 mL per cycle

Symbol

V_blood

Quantity

Average menstrual blood loss

Value

Days 1–5 (variable)

Symbol

d_mens

Quantity

Days of menstrual flow

Value

Days 6–14

Symbol

d_prol

Quantity

Days of proliferative phase

Value

Days 15–28

Symbol

d_secr

Quantity

Days of secretory phase

Term

Follicular phase (ovarian cycle)

Example

In a 35-day cycle, follicular phase lasts ~21 days (35 − 14); in a 21-day cycle, only ~7 days.

Definition

Days 1–13 (variable length) of cycle; FSH recruits and stimulates growth of ovarian follicles; dominant follicle emerges and secretes rising oestrogen.

Term

Ovulation

Example

LH surge detected on day 13 morning → ovulation likely occurs day 14 afternoon. Ovulation predictor kits detect LH surge to time intercourse.

Definition

Day ~14 of a 28-day cycle (varies with cycle length); LH surge ruptures mature follicle, releasing secondary oocyte; occurs ~24–36 hours after LH surge onset.

Term

Luteal phase (ovarian cycle)

Example

The luteal phase length is predictable; if cycle is 28 days, luteal phase is day 15–28 (~14 days); if 35 days, luteal phase is still ~14 days.

Definition

Days 15–28; remarkably constant at ~14 days (range 12–16 days); ruptured follicle becomes corpus luteum, secreting progesterone; if no pregnancy, corpus luteum regresses.

Term

Menstrual phase (endometrial cycle)

Example

Menstruation is triggered by progesterone withdrawal, not absolute hormone levels; if progesterone remains high, menses will not occur (basis for progesterone-only contraceptives).

Definition

Days 1–5 of cycle; functional layer of endometrium sheds due to falling oestrogen and progesterone (corpus luteum regression).

Term

Proliferative phase (endometrial cycle)

Example

Rising oestrogen promotes endometrial growth; endometrium thickens from ~2 mm (menstrual) to ~8–12 mm (ovulation).

Definition

Days 6–14; oestrogen-driven endometrial thickening and gland proliferation; ends at ovulation; also called follicular phase endometrially.

Term

Secretory phase (endometrial cycle)

Example

Endometrial glands become coiled ("corkscrew"), tortuous, and filled with glycogen and mucus; endometrial thickness remains ~8–12 mm.

Definition

Days 15–28; progesterone-driven transformation of endometrium into secretory, nutrient-rich tissue ready for implantation; also called luteal phase endometrially.

Term

Spinnbarkeit

Example

Cervical mucus transitions from thick (post-menstrual) → increased volume (proliferative) → peak spinnbarkeit (ovulation) → thick/reduced (secretory).

Definition

Clear, thin, stretchy (raw egg white–like) cervical mucus during fertile window; indicates high oestrogen and peak fertility.

Term

Mittelschmerz

Example

Some women use mittelschmerz as a sign of ovulation, though pain is not reliable for contraception (occurs in only ~20% of cycles).

Definition

Mid-cycle pelvic pain or cramping experienced by ~20% of women at or near ovulation; unilateral (side of ovulating ovary).

Term

Basal body temperature (BBT)

Example

BBT rise is RETROSPECTIVE proof of ovulation (not predictive); used to confirm ovulation has occurred after the fact.

Definition

Body temperature measured immediately upon waking; dips slightly before ovulation, then rises ~0.3–0.5°C after ovulation due to progesterone; remains elevated until menses.

Term

Corpus luteum

Example

If pregnancy occurs, hCG from trophoblast rescues corpus luteum, preventing regression; if no pregnancy, corpus luteum regresses to corpus albicans (white scar).

Definition

Endocrine structure formed from granulosa and theca cells of ruptured follicle; secretes progesterone and small amounts of oestrogen for ~14 days.

Term

Dominant follicle

Example

Multiple follicles are recruited, but only one becomes dominant (days 5–7); selection is driven by positive feedback of its own oestrogen on FSH receptors.

Definition

Single follicle (usually) that continues to grow and mature while others regress; has highest FSH receptor expression and produces peak oestrogen.

Formula

Fertile window ≈ 5 days before ovulation through 1 day after ovulation

Meaning

Period when unprotected intercourse can result in pregnancy

Watch Out

The fertile window is NOT fixed to days 12–16 of a 28-day cycle; it depends on when ovulation actually occurs in that individual.

When To Use

Counselling couples planning or avoiding pregnancy; basis for fertility awareness method (FAM) and natural family planning

Formula

Ovum viability = ~24 hours after ovulation

Meaning

Duration ovum remains capable of fertilisation in fallopian tube

Watch Out

Sperm are the primary determinant of fertile window length, not ovum; an ovum can be fertilised for ~24 hours, but sperm can wait 5 days.

When To Use

Explaining why timing of intercourse matters; sperm survival is much longer (48–72 hours)

Formula

Sperm viability in female tract = 48–72 hours (up to 5 days in fertile cervical mucus)

Meaning

Sperm can remain motile and capable of fertilisation for this period

Watch Out

Many contraceptive failures occur because couples underestimate sperm survival time (assume 24 hours); sperm can survive 5 days.

When To Use

Explaining pregnancy risk during days 1–5 of cycle or from intercourse 3–5 days before ovulation

Formula

Implantation timing = 6–10 days post-fertilisation (days 20–24 of 28-day cycle)

Meaning

Time from fertilisation to blastocyst embedding in endometrium

Watch Out

hCG is not detectable until implantation (days 6–10 post-fertilisation); early pregnancy tests may be falsely negative before implantation.

When To Use

Predicting when hCG becomes detectable (7–12 days post-ovulation); timing of pregnancy symptoms

Formula

hCG detection = 7–12 days post-ovulation (or 1–5 days post-implantation)

Meaning

Time when hCG reaches detectable levels in blood or urine

Watch Out

hCG doubles every 48–72 hours in early pregnancy; a single hCG level is less informative than serial measurements.

When To Use

Counselling on when to test for pregnancy; explaining false-negative early pregnancy tests

Value

~5 days before ovulation + 1 day after = ~6 days total

Symbol

t_fertile

Quantity

Fertile window length

Value

~24 hours after ovulation

Symbol

t_ovum_viable

Quantity

Ovum viability

Value

48–72 hours (up to 5 days in fertile mucus)

Symbol

t_sperm_viable

Quantity

Sperm viability in female tract

Value

Days 0–4 post-fertilisation

Symbol

t_cleavage

Quantity

Cleavage (zygote → morula)

Value

Days 4–5 post-fertilisation

Symbol

t_blastocyst

Quantity

Blastocyst formation

Value

Days 6–10 post-fertilisation (average day 8)

Symbol

t_implant

Quantity

Implantation timing

Value

48–72 hours in early pregnancy

Symbol

t_hCG_double

Quantity

hCG doubling time

Value

35 years (advanced), 40 years (very advanced)

Symbol

Age_maternal

Quantity

Minimum female age for advanced maternal age

Term

Fertilisation

Example

If sperm carries X chromosome, female offspring (46,XX); if Y chromosome, male offspring (46,XY).

Definition

Fusion of sperm nucleus (23 chromosomes) with secondary oocyte nucleus (23 chromosomes) to form zygote (46 chromosomes); occurs in ampulla of fallopian tube.

Term

Zygote

Example

Zygote undergoes cleavage (mitotic divisions without growth) to form morula (8–16 cells), then blastocyst (fluid-filled, ~100 cells).

Definition

Diploid cell (46 chromosomes) formed immediately after fertilisation; first cell of new organism.

Term

Morula

Example

Morula resembles a mulberry (morula = "little mulberry" in Latin); no growth in cell size, only division.

Definition

Stage of early embryo (3 days post-fertilisation) consisting of ~8–16 cells in solid mass; results from cleavage of zygote.

Term

Blastocyst

Example

Blastocyst "hatches" from zona pellucida before implantation; trophoblast secretes hCG to maintain corpus luteum.

Definition

Stage of early embryo (~4–5 days post-fertilisation) with ~100 cells; contains inner cell mass (ICM, future embryo) and trophoblast (future placenta); capable of implantation.

Term

Implantation

Example

Implantation is NOT complete until ~12 days post-fertilisation; early chemical pregnancy loss can occur before implantation is complete.

Definition

Embedding of blastocyst into endometrium; begins ~6–10 days post-fertilisation; trophoblast invades endometrium and forms placental villi.

Term

Ampulla

Example

If fertilisation occurs in isthmus (inner two-thirds), embryo is more likely to implant in tube (ectopic pregnancy); ampulla allows time for blastocyst development.

Definition

Widest, outer third of fallopian tube; site of fertilisation; has highest concentration of motile sperm due to peristalsis.

Term

Infertility

Example

Primary infertility = never conceived; secondary infertility = prior pregnancy but now unable to conceive.

Definition

Failure to conceive after 12 months of regular unprotected intercourse (or 6 months if female age >35 years).

Term

Fecundity

Example

Female fecundity at age 25 is ~25% per cycle; at age 40 it is ~10% per cycle; at age 45 it is ~3% per cycle.

Definition

Biological capacity to conceive and carry pregnancy to term; declines with advancing maternal age, especially after age 35.

Term

Ectopic pregnancy

Example

Risk factors include PID (scarring of tubes), previous ectopic pregnancy, IUD use, assisted reproductive technology (ART).

Definition

Implantation outside the uterus, most commonly in fallopian tube (99%); non-viable and life-threatening if ruptures.

Value

12–13 years (range 9–16 years)

Symbol

Age_menarche

Quantity

Normal menarche age

Value

No menses by age 15 years or 3 years post-breast development

Symbol

Age_prim_amen

Quantity

Primary amenorrhoea threshold

Value

Absence of menses for ≥3 months in prior menstruating woman

Symbol

t_sec_amen

Quantity

Secondary amenorrhoea definition

Value

>80 mL blood loss per cycle or >7 days duration

Symbol

Menorr_volume

Quantity

Menorrhagia threshold

Value

Cycle >35 days but <3 months

Symbol

t_oligomen

Quantity

Oligomenorrhoea definition

Value

Cycle <21 days

Symbol

t_polygen

Quantity

Polymenorrhoea definition

Value

12 consecutive months without menses

Symbol

t_menopause

Quantity

Menopause definition

Value

51 years (range 40–60 years)

Symbol

Age_menopause

Quantity

Average menopause age

Value

Menopause before age 40 years

Symbol

Age_prem_meno

Quantity

Premature menopause threshold

Term

Amenorrhoea (primary)

Example

Turner syndrome (45,X), müllerian agenesis, or severe eating disorder can cause primary amenorrhoea.

Definition

Absence of menarche (first menses) by age 15 years or 3 years post-breast development; indicates developmental delay.

Term

Amenorrhoea (secondary)

Example

Other causes: hypothalamic dysfunction (stress, weight loss), polycystic ovary syndrome (PCOS), thyroid disease, hyperprolactinaemia.

Definition

Cessation of menses for ≥3 months in a woman with prior normal menstruation; pregnancy is the most common cause.

Term

Dysmenorrhoea (primary)

Example

Cramping pain in lower abdomen, relieved by NSAIDs (mefenamic acid 500 mg, ibuprofen 400–600 mg) taken with food.

Definition

Painful menses with no identifiable pelvic pathology; caused by excess prostaglandin F2α (PGF2α) in endometrium; appears 1–2 years after menarche.

Term

Dysmenorrhoea (secondary)

Example

Deep infiltrating endometriosis or adenomyosis causes progressive dysmenorrhoea; requires imaging (ultrasound, MRI) and sometimes diagnostic laparoscopy.

Definition

Painful menses secondary to pelvic pathology such as endometriosis, fibroids, adenomyosis, or PID; often begins in 20s–30s.

Term

Menorrhagia

Example

Causes include fibroids, adenomyosis, coagulopathy, and hormone imbalances; treated with NSAIDs, tranexamic acid, or hormonal contraceptives.

Definition

Heavy or prolonged menstrual flow (>80 mL total blood loss per cycle or >7 days duration); increases anaemia risk.

Term

Metrorrhagia

Example

Postcoital bleeding raises concern for cervical pathology (polyps, cervicitis, cancer); postmenopausal bleeding requires endometrial evaluation.

Definition

Irregular uterine bleeding between periods (intermenstrual bleeding); suggests structural lesion, infection, or hormone imbalance.

Term

Oligomenorrhoea

Example

PCOS, thyroid disease, or extreme athletic training can cause oligomenorrhoea.

Definition

Infrequent, light menstrual periods; cycle >35 days but <3 months apart.

Term

Polymenorrhoea

Example

Short follicular phase (rare) or inadequate luteal phase can cause polymenorrhoea; associated with decreased fertility.

Definition

Abnormally frequent menstrual periods; cycle <21 days.

Term

Menopause

Example

Premature menopause (<age 40) is associated with Turner syndrome, fragile X, or autoimmune ovarian failure.

Definition

Permanent cessation of menstruation; diagnosed retrospectively after 12 consecutive months without menses; average age ~51 years.

Term

Perimenopause (climacteric)

Example

Cycle irregularity in perimenopause is normal; however, heavy bleeding or postmenopausal bleeding warrants evaluation.

Definition

Transitional years (usually 5–10 years) before menopause; marked by irregular cycles, declining oestrogen, and vasomotor symptoms (hot flushes, night sweats).

Term

Mittelschmerz

Example

Mittelschmerz can help identify ovulation but is not reliable for contraception; some women have it every cycle, others rarely.

Definition

Mid-cycle pelvic pain or cramping at or near ovulation (day ~14); occurs in ~20% of ovulatory cycles; unilateral (side of ovulating ovary).

Term

Spinnbarkeit

Example

Peak spinnbarkeit occurs 1–2 days before ovulation and is a sign of peak fertility; mucus viscosity changes are oestrogen-driven.

Definition

Clear, thin, stretchy cervical mucus with egg-white consistency during fertile window; stretches >6 cm between thumb and forefinger.

Term

Perineal hygiene

Example

Teach women to wipe front-to-back after voiding/defecation; back-to-front wiping introduces rectal flora (E. coli) toward urethra.

Definition

Proper vulva and perineal cleansing (front-to-back only) to maintain acidic vaginal pH and prevent UTI/reproductive infection.

Term

Fertility awareness method (FAM)

Example

Women track mucus changes (spinnbarkeit peak), BBT rise, and cycle length to avoid or achieve pregnancy; requires education and daily monitoring.

Definition

Natural family planning using cervical mucus, BBT, and calendar methods to identify fertile and infertile days; non-hormonal contraception.

Term

Timed intercourse

Example

Couples planning pregnancy are advised to have intercourse every 2–3 days or specifically on days 12–14 of a 28-day cycle (or adjusted for that couple's cycle length).

Definition

Intentional intercourse during fertile window to maximize conception probability; basis for fertility counselling and natural conception attempts.

Values

• Follicular phase
• Days 1–13 (variable)
• FSH rising, oestrogen rising
• Menstrual phase (days 1–5) + Proliferative phase (days 6–14)
• Shedding functional layer → Rebuilding and thickening endometrium

Property

Phase 1

Values

• Ovulation
• Day ~14 (variable)
• LH surge, oestrogen peak
• End of proliferative phase
• Endometrium reaches peak thickness (~8–12 mm) and vascularity

Property

Phase 2

Values

• Luteal phase
• Days 15–28 (fixed ~14 days)
• Progesterone dominates, oestrogen lower
• Secretory phase
• Endometrium becomes secretory (coiled glands, glycogen), maintains thickness, prepares for implantation

Property

Phase 3

Values

• Days 1–5
• Blood-tinged or absent
• Thick, scanty
• None or minimal
• Progesterone (declining), oestrogen (low)
• Infertile

Property

Menstrual phase

Values

• Days 6–10
• Creamy white/yellow
• Thick, opaque
• Minimal (<2 cm)
• Oestrogen (rising)
• Low fertility

Property

Early proliferative

Values

• Days 11–14
• Clear, transparent
• Thin, slippery (egg-white)
• Maximum (>6 cm, stretchy)
• Oestrogen (peak)
• HIGH FERTILITY (peak)

Property

Late proliferative (fertile window)

Values

• Day ~14
• Clear, transparent peak
• Maximally stretchy
• Maximum
• Oestrogen peak, LH surge
• MAXIMUM FERTILITY (ovulation day ± 1 day)

Property

Ovulation

Values

• Days 15–20
• Becoming thicker, white
• Thicker, curdled
• Decreasing
• Progesterone (rising)
• Declining fertility

Property

Early luteal

Values

• Days 21–28
• Thick, scanty, opaque
• Thick, sticky, minimal
• None
• Progesterone (high), oestrogen (low)
• Infertile

Property

Late luteal

Values

• ~30–35% of infertile couples
• Low sperm count (<15 million/mL), poor motility (<40% motile), poor morphology (<4% normal)
• Anovulation (no ovulation from PCOS, thyroid, hyperprolactinaemia), tubal blockage, endometriosis, poor endometrial receptivity

Property

Frequency ~1/3 each

Values

• ~30–35% of infertile couples
• Immunological (antisperm antibodies), genetic, sexual dysfunction
• Immunological, genetic, poor egg quality (age-related), uterine factors

Property

Combined/unexplained

Property

Initial workup

Values

• None (prostaglandin-mediated)
• Present (endometriosis, adenomyosis, fibroids, PID, IUD)

Property

Underlying pathology

Values

• 1–2 years after menarche (when ovulatory cycles begin)
• Later onset (20s–30s) or worsening of prior dysmenorrhoea

Property

Age of onset

Values

• Cramping, lower abdominal pain, radiates to lower back/thighs
• Severe, progressive, deeper pelvic pain, may include dyspareunia (painful intercourse)

Property

Pain character

Values

• Usually resolves within 2–3 days of menstruation onset
• May persist throughout cycle (adenomyosis) or worsen progressively (endometriosis)

Property

Duration

Values

• NSAIDs (mefenamic acid 500 mg TID, ibuprofen 400–600 mg TID) + heat
• NSAIDs + hormonal contraceptives (suppress ovulation/prostaglandins); may require diagnostic imaging or laparoscopy

Property

First-line treatment

Values

• Excellent (often 80–90% relief)
• Variable; depends on underlying cause

Property

Response to NSAIDs

Values

• No menarche (first menses) by age 15 years or 3 years post-breast development
• Cessation of menses for ≥3 months in woman with prior normal menstruation

Property

Definition

Values

• ~2–5% of women
• ~5–15% of women of reproductive age (varies by population)

Property

Prevalence

Values

• Constitutional delay, gonadal dysgenesis (Turner syndrome), müllerian agenesis
• Pregnancy (most common; rule out first!), hypothalamic dysfunction (stress, weight loss), PCOS

Property

Most common cause

Values

• Growth assessment, pubertal development staging, pelvic ultrasound, FSH/LH, karyotype if indicated
• Pregnancy test FIRST; then TSH, prolactin, LH/FSH, pelvic ultrasound if pregnancy negative

Property

Initial investigation

Values

• Often permanent (structural anomalies); functional causes may be reversible
• Often reversible if cause is functional (stress, weight loss); permanent if gonadal failure or structural

Property

Reversibility

Values

• Measure temperature immediately upon waking; rises ~0.3–0.5°C after ovulation due to progesterone
• Rise occurs 1–2 days AFTER ovulation (retrospective)
• ~80% when used with calendar method
• No cost, simple to perform
• RETROSPECTIVE proof only; cannot predict ovulation; requires consistency (wake at same time, record before getting up)

Property

BBT (basal body temperature)

Values

• Track mucus consistency; peak spinnbarkeit (clear, stretchy, egg-white) occurs 1–2 days before ovulation
• Peak mucus precedes ovulation by 1–2 days (predictive window)
• ~80–90% if woman is trained
• Predictive of ovulation; can identify fertile window before ovulation
• Requires daily self-assessment; learning curve; unreliable if cervicitis, hormonal contraceptives, or abnormal vaginal flora

Property

Cervical mucus (symptothermal method)

Values

• Detect LH surge in urine using home test kit; surge occurs 24–36 hours before ovulation
• Detects surge 1–2 days before ovulation (predictive)
• ~99% when used correctly
• Most accurate; urine testing is convenient and quick (result in 5 minutes)
• Cost (~$10–20 per kit, need multiple per cycle); can miss surge if urine diluted or timing off; relies on regular cycle

Property

LH surge (ovulation predictor kit)

Values

• 21–35 days
• 2–7 days
• 30–80 mL
• NORMAL

Property

Normal

Values

• >35 days to <3 months
• Variable
• Often light
• ABNORMAL FREQUENCY (infrequent)

Property

Oligomenorrhoea

Values

• <21 days
• Variable
• Variable
• ABNORMAL FREQUENCY (frequent)

Property

Polymenorrhoea

Values

• Absent ≥3 months
• N/A
• N/A
• ABNORMAL FREQUENCY (absent)

Property

Amenorrhoea

Values

• Normal (21–35 days)
• >7 days
• >80 mL per cycle
• ABNORMAL FLOW (heavy/prolonged)

Property

Menorrhagia

Values

• Normal (21–35 days)
• Shortened (<2 days)
• <30 mL per cycle
• ABNORMAL FLOW (light/short)

Property

Hypomenorrhoea

Values

• Irregular (bleeding between periods)
• Irregular
• Variable
• ABNORMAL PATTERN (intermenstrual bleeding)

Property

Metrorrhagia