Introduction
The polycystic ovary syndrome (PCOS) is a heterogeneous
condition, the pathophysiology of which appears to be both
multifactorial and polygenic. The definition of the syndrome
has been much debated. Key features include menstrual cycle
disturbance, hyperandrogenism and obesity. There are many
extra-ovarian aspects to the pathophysiology of PCOS, yet
ovarian dysfunction is central. At a joint ASRM/ESHRE
consensus meeting, a refined definition of the PCOS was
agreed, in which two out of the following are required:
N
oligomenorrhoea or amenorrhoea;
N
clinical and/or biochemical signs of hyperandrogenism;
N
polycystic ovaries, once appropriate tests have been
performed to exclude other causes of androgen excess
and menstrual disturbance.
1
According to the available literature, the criteria fulfilling
sufficient specificity and sensitivity to define the polycystic
ovary (PCO) should have at least one of the following: either 12
or more follicles measuring 2–9 mm in diameter or increased
ovarian volume (
.
10 cm
3
). If there is a follicle
.
10 mm in
diameter, the scan should be repeated at a time of ovarian
quiescence in order to calculate volume and area. The
presence of a single PCO is sufficient to provide the diagnosis.
The distribution of follicles and a description of the stroma are
not required in the diagnosis.
2
Increased stromal echogenicity
and/or stromal volume are specific to PCO, but it has been