Lecture 2 - Menstruation Flashcards
What is the origin of the term menstruation and why?
- Latin mensis = month and Greek mene = moon
- Monthly cycle similar to lunar phase
What are the 2 purposes of menstruation?
- Support to release egg in ovulation
- Support to prepare for pregnancy
What species does menstruation occur in?
Humans, primates, some rodents eg bats
List the part of the brain that controls menstruation and the hormones involved
- Hypothalamus pituitary ovarian (HPO) axis
- Gondaotropin releasing hormone (GnRH)
- Gonadotropins = luteinising hormone (LH) and follicle stimulating hormone (FSH)
Describe the follicular phase - days, hormones, features
- Days 1-13/14 beginning with menstruation
- Increased FSH
- Low LH, estrogen, progesterone
- Lower body temp with dip before ovulation
- Ends when LH surges
Describe the proliferative phase - days, hormones, features
- Days 7-13/14
- Increaseed FSH declines as follicles develop
- Follicle produces estrogen
- Uterine lining begins to thicken
Describe the ovulatory phase - days, hormones, features
- Start = surge in LH and FSH
- LH surge = ovulation after 10-12 hrs
- GnRH surge = estrogen declines, progesterone increases
When is the fertile window and how long it is?
- 5 days before ovulation to 1 day after
- 16-32 hrs long
Describe the luteal/secretory phase - days, hormones, features
- Day 13/14 - 28
- LH and FSH decrease
- Estrogen and progesterone high = thicken lining
- Ruptured follicle closes = corpus luteum producing progesterone
What happens to the corpus luteum if fertilisation happens vs if it doesn’t?
- Fertilisation = maintains pregnancy
- None = degenerates = progesterone and estrogen decreases = menstruation
Describe the features of a normal menstrual cycle
- Menarche <16yrs
- Menopause >45yrs
- Menstruation 3-8days
- Blood loss <80mL
- Cycle length 24-38days
- No intermenstrual bleeding (IMB)
What are the signs of ovulation?
- Egg white texture cervical mucus
- Mittelschermz feeling
- Bloating
- Headache
- Increase body temp
- LH detectable in samples and kits
What is the egg checker test and what are its limitations?
Anti-Malarial hormone (AMH) test to check egg reserve
Doesn’t show egg quality or a fertility prediction
What are the features of menarche and perimenopause that are similar?
Irregular periods, low chance of pregnancy, ovulation not every cycle, HPO axis not perfect
Why did women in the early 20th century have less periods, late menarche and early menopause?
Took longer to reach healthy weight, more pregnancies, breastfeeding
What factors influence menarche and menopause?
- Menarche = BMI, health, environment, genetics/race, geography, psychology
- Menopause = BMI, health, environment, menarche age, preganancies, oral contraceptives
Why do menstrual disorders arise? What are the 3 main changes?
- Body isn’t ready to support pregnancy for various reasons eg stress, malnourished
- Volume, regularity, frequency
What is heavy menstrual bleeding (HMB) or menorrhagia? What are the causes and management?
- What = excessive bleeding with/without other symptoms and impacting quality of life
- Features = 80+ mL, large clots, 7+ days, anaemia
- Pathological growths or reasons and non-pathological
- Management = IUD or anti-fibrinolytics/tranexamic acid and NSAIDs
What is absent menstrual bleeding or amenorrhoea? What are the 2 types and their causes?
- What = absent mensturation by 16yo ie menarche
- Primary physio from late puberty or path from hormones, outflow problems, genetic
- Secondary physio from pregnancy, lactation, menopause or path from hormones, outflow problems
What is infrequent menstrual bleeding or oligomenorrhoea? What are the causes?
- What = infrequent bleeding 35days-6months
- Causes = premature menopause, PCOS, hyperprolactinaemia from hormonal disruption
What is premenstrual syndrome (PMS) and how does it differ from premenstrual dysphoric disorder (PMDD)?
- PMS = decrease in estrogen and progesterone, iron loss, inflammation and pain but manageable with small interventions
- PMDD = rare severe disorder often comboed with anxiety/depression and needing doctor management
What is dysmenorrhoea and its cause?
Painful periods from high prostaglandin in endometrium, contraction, uterine ischaemia
What are the options for menstrual hygiene and how does access and cultural norms impact menstrual health?
- Disposable pads, tampons, resusable cloths, underwear, menstrual cup, reusable pads
- Difficult to manage menstruation in cultures that see it as taboo = women don’t understand their cycle
- No awareness = stigma
