Biology of Disease

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patients with PCOS suffer from acne, obesity, type 2 diabetes mellitus and may
be infertile. A diagnosis of PCOS is made on clinical grounds and assisted by
ultrasonography. Plasma LH is often increased in these patients but may be
normal, whereas the concentration of testosterone is increased. Treatment of
severe PCOS may involve using the antiandrogen drug, cyproterone but this
leads to infertility. If fertility is required, then clomiphene, an antiestrogen
drug, may be used and can induce ovulation in 75% of cases.

Infertility


Infertility is defined as a failure to conceive despite regular unprotected sexual
intercourse for one year. Female infertility may be due to failure to ovulate,
obstruction of the Fallopian tubes or to diseases of the uterine lining. In
females, failures to ovulate due to hyperprolactinemia or to hypothalamic-
pituitary dysfunction are responsible for 20% of cases of infertility. Damage
to the Fallopian tubes may also be a cause of female infertility. Male infertility
is usually due to decreased numbers or motility of sperm (oligospermia)
or complete absence of sperm (azoospermia). Infertility due to endocrine
dysfunction occurs only rarely in males. The normal volume of ejaculate is

REPRODUCTIVE HORMONES

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Clinical history and
examination

Normal menses OligomenorrheaAmenorrhea

Perform
pregnancy
test

Positive

Negative

Measure [FSH], [LH]
and [prolactin] in serum

No further
tests required

Normal
ovulation

<10 nmol dm-3


30 nmol dm-3



Not ovulating

High FSH
High LH

High LH
Low FSH

High
prolactin

Normal FSH
Normal LH
Normal prolactin

Ovarian
failure

Polycystic ovary
syndrome

Investigate for
hyperprolactinemia

Further investigations
required

Measure [progesterone]
in serum to confirm
ovulation

Figure 7.41 Overview of the investigation of amenorrhea.
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