Amenorrhoea_Flashcards
What is primary amenorrhoea?
Primary amenorrhoea is defined as the failure to establish menstruation by 15 years of age in girls with normal secondary sexual characteristics, or by 13 years of age in girls with no secondary sexual characteristics.
What is secondary amenorrhoea?
Secondary amenorrhoea is the cessation of menstruation for 3-6 months in women with previously normal and regular menses, or 6-12 months in women with previous oligomenorrhoea.
What are the common causes of primary amenorrhoea?
Common causes of primary amenorrhoea include gonadal dysgenesis (e.g. Turner’s syndrome), testicular feminisation, congenital malformations of the genital tract, functional hypothalamic amenorrhoea (e.g. secondary to anorexia), congenital adrenal hyperplasia, and imperforate hymen.
What are the common causes of secondary amenorrhoea (after excluding pregnancy)?
Common causes of secondary amenorrhoea (after excluding pregnancy) include hypothalamic amenorrhoea (e.g. secondary to stress, excessive exercise), polycystic ovarian syndrome (PCOS), hyperprolactinaemia, premature ovarian failure, thyrotoxicosis, Sheehan’s syndrome, and Asherman’s syndrome (intrauterine adhesions).
What are the initial investigations for amenorrhoea?
Initial investigations for amenorrhoea include excluding pregnancy with urinary or serum bHCG, full blood count, urea & electrolytes, coeliac screen, thyroid function tests, gonadotrophins, prolactin, androgen levels, and oestradiol.
What do low levels of gonadotrophins indicate?
Low levels of gonadotrophins indicate a hypothalamic cause.
What do raised levels of gonadotrophins suggest?
Raised levels of gonadotrophins suggest an ovarian problem (e.g. premature ovarian failure).
What condition is indicated by raised gonadotrophins and gonadal dysgenesis?
Raised gonadotrophins and gonadal dysgenesis indicate Turner’s syndrome.
What condition might raised androgen levels indicate?
Raised androgen levels may indicate polycystic ovarian syndrome (PCOS).
What are the management steps for primary amenorrhoea?
Management steps for primary amenorrhoea include investigating and treating any underlying cause.
What specific treatment might benefit those with primary ovarian insufficiency due to gonadal dysgenesis?
Those with primary ovarian insufficiency due to gonadal dysgenesis (e.g. Turner’s syndrome) are likely to benefit from hormone replacement therapy.
What are the management steps for secondary amenorrhoea?
Management steps for secondary amenorrhoea include excluding pregnancy, lactation, and menopause (in women 40 years of age or older) and treating the underlying cause.
Which other thyroid condition may also cause amenorrhoea?
Hypothyroidism may also cause amenorrhoea.
summarise amenorrhoea
Amenorrhoea
Amenorrhoea may be divided into:
primary: defined as the failure to establish menstruation by 15 years of age in girls with normal secondary sexual characteristics (such as breast development), or by 13 years of age in girls with no secondary sexual characteristics
secondary: cessation of menstruation for 3-6 months in women with previously normal and regular menses, or 6-12 months in women with previous oligomenorrhoea
Causes
Primary amenorrhoea Secondary amenorrhoea (after excluding pregnancy)
gonadal dysgenesis (e.g. Turner’s syndrome) - the most common causes
testicular feminisation
congenital malformations of the genital tract
functional hypothalamic amenorrhoea (e.g. secondary to anorexia)
congenital adrenal hyperplasia
imperforate hymen
hypothalamic amenorrhoea (e.g. secondary stress, excessive exercise)
polycystic ovarian syndrome (PCOS)
hyperprolactinaemia
premature ovarian failure
thyrotoxicosis*
Sheehan’s syndrome
Asherman’s syndrome (intrauterine adhesions)
Investigation and management
Initial investigations
exclude pregnancy with urinary or serum bHCG
full blood count, urea & electrolytes, coeliac screen, thyroid function tests
gonadotrophins
low levels indicate a hypothalamic cause where as raised levels suggest an ovarian problem (e.g. Premature ovarian failure)
raised if gonadal dysgenesis (e.g. Turner’s syndrome)
prolactin
androgen levels
raised levels may be seen in PCOS
oestradiol
Management
primary amenorrhoea:
investigate and treat any underlying cause
with primary ovarian insufficiency due to gonadal dysgenesis (e.g. Turner’s syndrome) are likely to benefit from hormone replacement therapy (e.g. to prevent osteoporosis etC)
secondary amenorrhoea
exclude pregnancy, lactation, and menopause (in women 40 years of age or older)
treat the underlying cause
*hypothyroidism may also cause amenorrhoea
A 17-year-old girl is brought in due to parental concerns about lack of menstruation. All her school friends have already started their periods and they are worried that there may be something wrong with her.
Blood tests show the following:
FSH 12 IU/L (4-8)
LH 13 IU/L (4-8)
What is the most likely underlying diagnosis?
Noonan syndrome
Normal late menarche
Polycystic ovarian syndrome
Pregnancy
Turner syndrome
Turner syndrome
Raised FSH/LH in primary amenorrhoea - consider gonadal dysgenesis (e.g. Turner’s syndrome)
Turner syndrome is the most likely underlying cause of this girl’s amenorrhea. In Turner syndrome, one of the two X chromosomes is missing in a female. Physical signs may include a short and webbed neck, low-set ears, low hairline at the back of the neck, short stature, and swollen hands and feet noted at birth. Typically, patients do not develop menstrual periods and breasts without hormone treatment and are unable to have children without reproductive technology. However, the incidence of spontaneous puberty varies between 8-40% depending on whether or not there is a complete or partial absence of the X chromosome. Turner syndrome is a common cause of primary amenorrhea. Genetic studies would confirm the diagnosis.
Noonan syndrome is an autosomal dominant condition that may present with mildly unusual facial features, short height, congenital heart disease, bleeding problems, and skeletal malformations. Facial features include widely spaced eyes, light-colored eyes, low-set ears, a short neck, and a small lower jaw. Common heart problems may include pulmonary valve stenosis. The breast bone may either protrude or be sunken, while the spine may be abnormally curved. Noonan syndrome is similar in some ways to Turner syndrome, but it often affects boys. It is far less common than Turner syndrome as a cause of primary amenorrhea in girls and therefore is not the most likely diagnosis.
Normal late menarche is incorrect. While some girls start their menstruation later and this may be physiological, they would not have deranged LH and FSH. These point to a potential underlying pathology that warrants further investigation.
Polycystic ovarian syndrome (PCOS) is not the most likely diagnosis here, but it is a common cause of secondary amenorrhoea. In PCOS, LH is disproportionately high compared to FSH. Normally this ratio is about 1:1, but for women with PCOS, the ratio may be 2:1 or 3:1.
Pregnancy is an important differential to consider as the girl may not have disclosed sexual activity to her parents. However, the girl has never had a period and so is unlikely to be fertile. Furthermore, the follicle-stimulating hormone (FSH) is suppressed during pregnancy, which would not be in keeping with her blood test results.
