Lecture 9: Introduction to menstrual disorders Flashcards
What is amenorrhoea?
Absence of menstruation, so can be normal (childhood, pregnancy, menopause), but can be pathological
What are the different types of amenorrhoea?
Both are quite rare
Primary: when menstruation has not yet started by the age of 16 in the presence of normal secondary characteristics (RARE)
Secondary: absent periods for 6 months who previously had regular periods, or 12 months if she has oligomenorrhoea (bleeds less frequently than 6 weekly) (MORE COMMONLY SEEN)
What is the main difference in causes between primary and seconary amenorrhoea?
Secondary usually to do with the HPG axis and you have had your period before
Primary could also involve problems with the genitalia
What are the causes of primary amenorrhoea?
-can just be due to a constitutional delay of puberty
-most common causes are genitourinary malformations (anatomical causes) if there are secondary characteristics
e.g. imperforate hymen, vaginal septum (longitudinal or transverse), absent vagina, absent uterus
If there are no secondary sexual characteristics it is usually due to a chromosomal/hormonal cause
e.g. turners syndrome, CAIS, hypothalamic-pituitary dysfunction
What is an imperforate hymen?
Congenital disorder where a hymen without an opening obstructs the vagina. Caused by failure of hymen to perforate during fetal development.
-most often diagnosis is in adolescent girls when menstrual blood accumulates in the vagina and sometimes the uterus
What is turners syndrome?
45 XO (loss of one of the X chromosomes)
- ovary does not complete its development (dysgenesis)
- no oestrogen produced so no pubertal changes
- high FSH and LH
What is complete androgen insensitivity syndrome (CAIS)?
- X linked recessive
- resistance to testosterone due to defect in the androgen receptor
- 46 XY but normal female phenotype (external)
- absence of upper vagina, uterus, and fallopian tubes
- testes should be surgically excised after puberty
What are the causes of secondary amenorrhoea?
- scarring
- ashermans syndrome (intrauterine adhesions)
- primary ovarian insufficiency (premature menopause) where there is depletion of oocytes before 40 yo, there is no oestrogen or inhibin=high FSH due to loss of negative feedback
- PCOS (polycystic ovarian syndrome): elevated LH, raised insulin resistance, may be asymptomatic, multiple small follicles on the ovaries
- thyroid disease
- hyperprolactinemia
What is the PCOS triad?
- mesntrual irregularlity
- androgen excess (can cause acne/hirsutism)
- obesity (diabetes and cardiovascular risk)
How does thyroid disease cause secondary amenorrhoea?
In both hypothyroidism and hyperthyroidism but predominantly hyperthyroidism
-may be due to the fact that the changes in the thyroid hormones have an impact on the HPG axis
How does hyperprolactinemia cause secondary amenorrhoea?
-raised prolactin levels
-high prolactin levels intefere with normal production of oestrogen and progesterone which can stop ovulation
Causes
-pituitary tumours (prolactinomas)
-hypothyroidism
-some medicines for depression, psychosis and high BP
What are some examples of hypothalamic and pituitary diseases that cause secondary amenorrhoea?
- prolactinoma (treated with dopamine, as it inhibits prolactin)
- pituitary necrosis
- weight loss
- emotional stress/stress caused by illness
What are some diseases in the hypothalamus/pituitary that cause primary amenorrhea?
Isolated GnRH deficiency (idiopathic hypogonadotrophic hypogonadism)
-no secondary sexual characteristics (this can be associated with loss of smell (anosmia) which is Kallman syndrome)
What are some examples of physiological amenorrhoea?
- pregnancy
- menopause
What is meant by abnormal uterine bleeding?
Uterine bleeding that is:
- duration greater that 8 days
- flow greater than 80ml/cycle or heavier than normal flow
- occur more frequently than every 24 days or less frequently than every 38 days
- intermesntrual bleeding/postcoital spotting
- absence of menses