Normal Menstruation

1. Normal Menstruation
Aboubakr Elnashar
Benha university Hospital, Egypt
ABOUBAKR ELNASHAR

2. The process
Complex
aspects of its initiation, control, and cessation:
not fully understood.
The average ages: menarche: 12.8 y
menopause: 51 y
Day 1 of a cycle:
first day of fresh bleeding and this should always
be clarified on history of LMP.
ABOUBAKR ELNASHAR

3. Follicular phase
Pulsatile release of
hypothalamic GnRH: anterior
pituitary to produce FSH.
 FSH promotes ovarian
follicular development:
recruitment of a dominant follicle
containing oocyte.
 Follicular granulosa cells
produce oestrogen: endometrial
proliferation.
Inc oestrogen levels: -ve
feedback on the hypothalamo-
pituitary (HP) axis (via follicular
inhibin) to stop further FSH
production. ABOUBAKR ELNASHAR

4. Ovulation
Increasing dominant follicle oestrogen (positive
feedback via follicular activin): altered
hypothalamic GnRH pulsatility: pituitary production
of LH: LH surge 36h before ovulation.
ABOUBAKR ELNASHAR

5. Luteal phase
The follicle collapses down to become the corpus
luteum (CL) ('yellow body'), which produces
oestrogen and progesterone (from theca cells).
Progesterone and oestrogen act on an
oestrogen-primed endometrium to induce
secretory changes: thickening and inc vascularity.
The corpus luteum has a fixed lifespan of 14 days
(programmed cell death) before undergoing
involution: corpus albicans ('white body').
ABOUBAKR ELNASHAR

6. ABOUBAKR ELNASHAR

7. ABOUBAKR ELNASHAR

8.  If implantation occurs:
hCG (luteotrophic) 'rescue' of the CL allows
continued production of progesterone to support
the endometrium.
 In the absence of pregnancy:
CL degeneration: a rapid fall in progesterone and
oestrogen, initiating menstruation.
ABOUBAKR ELNASHAR

9. Menstrual phase
Rapid dec in steroids: shedding of the unused
endometrium.
Inflammatory mediators (PGs, ILs, and tumour
necrosis factor (TNF): vasospasm (approx. 24h) in
spiral end arteries: hypoxia and endometrial
devitalization.
Vasodilatation and spiral artery collapse: loss of
the layer and bleeding from vessels
Endometrium lost down to basalis layer (1/3 of
loss reabsorbed).
ABOUBAKR ELNASHAR

10. Complex vascular changes controlled by above
secondary messengers, also: natural haemostatic
mechanisms including platelet plugs, coagulation
cascade, and fibrinolysis.
All steroid hormones now at basal level, negative
feedback is lifted, and GnRH-FSH production can
begin a new cycle.
ABOUBAKR ELNASHAR

11. Normal cycle or pathological?
Ovulatory cycles
•Regular
•usually 21-32 days
{variable follicular phase} (luteal phase fixed).
•Shorter or longer cycles usually result from oligo-
ovulationl/ anovulation.
After menarche:
• Cycles often irregular for months or for several
years
• {immaturation of the HPO axis}
ABOUBAKR ELNASHAR

12. Peri-menopausal periods
•Commonly irregular (usually inc cycle length)
•{ovarian resistance to gonadotrophins and
anovulatory cycles}.
>45yrs
•irregular, chaotic, or constant bleeding:
•investigation to exclude genital tract cancer.
ABOUBAKR ELNASHAR

13. Bleeding
Duration
1-7days with an average of 3-5 days.
Amount
•highly variable.
•Periods described as 'heavy' should always be
viewed as such.
Abnormal
•lMB
•PCB
•totally erratic/constant bleeding
ABOUBAKR ELNASHAR

14. Pain
Normal
{vasospasm and ischaemia}
highly variable.
Abnormal: interfering with normal functioning
needs
ABOUBAKR ELNASHAR

15. ABOUBAKR ELNASHAR