Fertility potential declines with age. Peak fertility is usually in the 20s, then an accelerated decline occurs from the mid-30s. From the 4th decade onwards, only a small number of women will conceive spontaneously.
The cause of PCOS is not known, but sometimes runs in families. The symptoms are related to abnormal hormone production (hence the term hormone imbalance). The diagnosis is made following typical symptoms, hormone tests and ultrasound imaging of the ovaries.