Since PCOS is by far the commonest cause of anovulation, most treatments are geared towards inducing ovulation in women with PCOS.
Lifestyle change and weight loss:
A very important intervention in overweight anovulatory women with PCOS is lifestyle change aimed at losing weight. In some cases, weight loss alone is enough to correct the hormonal imbalance in PCOS and bring about ovulation.
Letrozole:
Recent international PCOS guidelines recommend that the first line medical treatment for inducing ovulation should be letrozole (Femara). Letrozole belongs to a family of drugs known as aromatase inhibitors, which are best known for treating hormonally-responsive breast cancer. By blocking oestrogen production, letrozole tricks the body into producing more FSH, which causes follicle growth and leads to ovulation. Letrozole is taken in tablet form for 5 days with ovulation expected to occur around 6-8 days after the last tablet.
Clomiphene citrate:
The most widely used ovulation induction agent is clomiphene citrate (Clomid). Clomiphene causes an increase in the body’s own FSH levels to promote follicle development. It is taken in tablet form for 5 days with ovulation expected to occur around 6-8 days after the last tablet.
Metformin:
Metformin (Glucophage) helps the body to use insulin more effectively and is used to treat diabetes. This benefits some women with PCOS since with PCOS, there is often resistance to the action of insulin. Metformin is less effective than either letrozole or clomiphene for inducing ovulation.
FSH injections:
If oral medications fail, the next step is to directly administer FSH. FSH is administered daily by injection under the skin (subcutaneous). Compared with oral medications, there is a higher risk of causing too many follicles to develop with FSH injections so this treatment requires very close monitoring.
Laparoscopic ovarian “drilling”:
Another option for increasing ovulation, and the sensitivity of ovaries to ovulation induction drugs, is ovarian “drilling”. This is a surgical procedure typically performed via laparoscopy in which small holes are drilled in the ovarian surface using electricity delivered by a surgical point electrode.
Other treatment options:
Treatment for other causes of anovulation should target the underlying defect. In cases of hyperprolactinaemia, ovulation induction can be brought about by reducing prolactin levels using drugs such as bromocriptine (Parlodel) and cabergoline (Dostinex). Pituitary tumours producing prolactin may need to be surgically removed, especially if they are large and associated with visual disturbances.
In cases of hypothalamic amenorrhoea associated with low body weight, restoration of weight into the normal range can be effective, but may not be easy to achieve. In these and other cases where FSH and LH are lacking, both of these hormones (or an equivalent) can be administered by injection under the skin. In some countries, GnRH is a treatment option and is administered using a pump system that automatically delivers GnRH under the skin at a pre-determined rate.