The Menstrual Cycle Flashcards
Name the three phases of the menstrual cycle and the days that they occur.
Day 1-4: Menstruation
Day 5-13: Proliferative phase
Day 14-28: Secretory/luteal phase
List the hormonal changes of the menstrual cycle.
Hormonal support withdrawn –> menstruation
Proliferative phase
GnRH –> LH and FSH release from anterior pituitary
–> follicular growth –> which then produce oestradiol and inhibin
Oestradiol and inhibin cause neg feedback on FSH –> only one follicle (and therefore one oocyte) matures
Oestradiol also causes endometrium to proliferate (stromal cells proliferate and glands elongate)
Oestradiol causes positive feedback on LH
LH surge when oestradiol at max
ovulation triggered, occurs 36 hours after LH surge
Secretory Phase Follicle --> corpus luteum Produces oestradiol and progesterone Peak progesterone at day 21-28 Causes secretory changes, stromal cells enlarge, glands swell, blood supply increases Corpus luteum starts to fail if fertilisation hasn't occurred Endometrium breaks down Cycle starts again
Normal Menstruation Limits
Menarche <16 years
Menopause >45 years
Menstruation <8 days in length
Blood loss <80ml
Cycle length 23-35 days
No intermenstrual bleeding
Definition of Oligomenorrhoea
Cycle length >35 days - 6 months
After 6 months = secondary amenorrhoea
PCOS most common cause
Definition of primary and secondary amenorrhoea
Primary: absence of menstruation despite puberty >16 years of age
(may be manifestation of delayed puberty which is lack of secondary sex characteristics >14 yrs)
Can be due to outflow problem if secondary sex characteristics present
Secondary: absence of menstruation for 3-6 months in women who has previously menstruated
Pregnancy most common
Also caused by: stress, High/Low BMI, exercise, prolactinoma
Menorrhagia
Definition: excessive bleeding in an otherwise normal menstrual cycle
Clinical: Excessive menstrual loss that interferes with a women’s physical, emotional, social and material quality of life
Objective: >80ml blood loss in otherwise normal menstrual cycle (cut-off for amount lost without anaemia)
Causes Uterine fibroids: 30% Polyps: 10% PID, ovarian tumours, endometrial/cervical malignancy Malignancy --> irregular bleeding Thyroid disorders Haemostatic disorders (vWD) (think if excessive bruising or bleeding after trauma/surgery) Anticoagulant therapy
Inv:
Hb
Coagulation
TFTs
TVUS (endometrial thickness, exclude fibroids)
>10mm endometrium or polyp suspected OR >40 with recent onset menorrhagia or IMB –> endometrial biopsy at hysteroscopy or Pipelle
Hysteroscopy: allows inspection and detection of polyps and submucosal fibroids
Management of Menorrhagia
Management
Exclude pathology
Depends on women’s contraceptive needs
MEDICAL MX
1st Line - IUD: reduces mesntrual flow by 90%, fewer side effects vs systemic progesterone
2nd Line
Antifibrinolytics (Tranexamic Acid) - taken during menstruation only
Reduce fibrinolytic activity, reduce blood loss by 50%
Available without prescription
NSAIDS
Mefenamic acid
Reduce blood loss by 30% and good for dysmenorrhoea
Side effects: as for aspirin
COCP
Induce lighter menstruation
Less effective if pelvis pathology present
Limited due to complications in older patients, smokers etc.
3rd Line
Progestogens
High dose IM or PO –> amenorrhoea
GnRH agonists produce amenorrhoea
Need to use add-back HRT otherwise symptoms of menopause
Bleeding follows withdrawal
SURGICAL MX
Hysteroscopy
-Polyp removal
- Endometrial ablation techniques
- -Appropriate for older women with endometrius <10 week size
- -Not a form of sterilization
- -Amenorrhoea or light periods follow
- Transcervical Resection of Endometrium
- Microwave and balloon ablation –> lower risk of perforation
- Transcervical resection of fibroids
- -Submucosal fibroids <3cm
- -reduce menstrual flow and improve fertility
- -Can perform TCRE at same time if fertility not wanted
More Radical
Myomectomy : open or laparoscopic
Used if fibroids causing symptoms but fertility wanted
GnRH used to shrink fibroids first
Hysterectomy
Last resort
Vaginal, laparoscopic or abdominal
Uterine artery embolization
Treats menorrhagia due to fibroids
Indications for endometrial biopsy with Menorrhagia
- Endometrial thickness >10mm in premenopausal or >4mm in postmenopausal
- Age >40 years
- Menorrhagia with IMB
- US suggests polyp
- Before insertion of IUD if cycles irregular
- Prior to endometrial ablation as tissue will not be available for biopsy
- Abnormal uterine bleeding resulting in acute admission
Irregular Bleeding and Intermenstrual Bleeding
CAUSES
Anovulatory Cycle
Common in extremes of reproductive years
Just after menarche and before menopause
Pelvic Pathology
Non Malignant: fibroids, uterine/cervical polyps, adenomyosis, ovarian cysts, chronic pelvic inflammatory disease,
Malignant: ovarian, cervical and endometrial
Suspect in older women with recent change
INVX
Assessment for menorrhagia and speculum might reveal cervical polyp
Hb
Cervical smear
Exclude malignancy: USS for women >35 years with irregular/IBM OR Treatment resistant in younger women
Pipelle biopsy
Hysteroscopy if >40, endometrium thickened, polyp suspected, or if ablative surgery to be used
Management of Irregular Bleeding and Intermenstrual Bleeding
Drugs: used for anovulation
COCP or IUD
High dose progesterone can be used ==> given cyclically can mimic normal menstruation
HRT if menopausal
Surgery
Cervical polyp –> send for histology
Same as for menorrhagia
Ablation etc.
Causes and Mx of Post-Coital Bleeding
Cervical carcinoma
Cervical ectropion
Cervical polyps
Cervicitis, vaginitis
Atrophic vaginal wall bleed
Mx
Cervical smear
Avulsion of polyp and histology
Ectropion can be frozen with cryotherapy
If none of the above cause –> Colposcopy to check for malignancy
Dysmenorrhoea
Primary
No cause identified
Coincides with start of menstruation
Mx: Reassure, NSAIDs or ovulation suppression with COCP
If medical treatment fails pelvic pathology more likely
Secondary
Pain precedes and is relieved by menstruation
Deep dyspareunia and menorrhagie/irregular menstruation commonly associated
Causes: Fibroids, Adenomyosis, Endometriosis, PID and ovarian tumours
Laparoscopic nerve ablation not helpful
Mx: Pelvic USS, Laparoscopy
Precocious Puberty
Menstruation <10 years
Secondary sexual characteristics <8 years
Growth occurs early but final height reduced as epiphyses fuse early
80% idiopathic
Central causes: encephalitis, meningitis, CNS tumours, hydrocephaly and hypothyrpidism
Ovarian/Adrenal causes: Increased oestrogen secretion, hormone producing tumour of ovary/adrenal,
McCune Albright Syndrome
Mx
Treat cause
GnRH agonists prevent sex hormone secretion –> arrest maturation until later age
McCune Albright Syndrome
Polyostotic fibrous dysplasia.
Café-au-lait skin pigmentation.
Autonomous endocrine hyperfunction (including precocious puberty, thyrotoxicosis, pituitary gigantism and Cushing’s syndrome)
Mx: Cyproterone acetate
GnRH not used an GnRH independent cause
Ambiguous Sexual Development and Intersex
Increased Androgen Function in Genetic Female
Congenital adrenal hyperplasia:
