At least 20 per cent of women attending infertility clinic will have a problem relating to ovulation. Clomiphene is the treatment of choice for patients where ovulation is defective ie. not ovulating or ovulating very infrequently or irregularly. In some cases it may be offered to patients who are ovulating but where no cause of infertility has been found from all the routine investigations ie. couple with unexplained infertility.
Clomiphene works best when there is adequate amounts of oestrogen (hormone) being produced by the woman.
Clomiphene is very similar to oestrogen in structure. This indirectly results in the pituitary gland producing higher level of FSH, a hormone which subsequently leads to ovarian stimulation and hence ovulation.
Administration of Clomiphene
Treatment starts with a single 50mg tablet daily for five days, usually commencing on the second day of the period. The dosage may be increased in subsequent cycles by taking two tablets per day (100mgs) up to a maximum of three tablets a day (150mgs) for five days, if the response is inadequate
on the lower dose.
In practice most patients ovulate on 50 to 100mg dose. Once ovulation has been achieved as shown by a blood test (progesterone level) the treatment is
maintained at the same does for six cycles (occasionally up to a maximum of 12 cycles).
Effectiveness of Clomiphene therapy
On Clomiphene therapy 80 to 90 per cent of women ovulate with a pregnancy rate of more than 50 per cent.
There is 1:16 chance (approximately six per cent) of a multiple pregnancy on Clomiphene and most of these will be twins and occasionally triplets.
There is no demonstrable increase in the abnormality rate of babies conceived with this treatment nor is there an increased rate of spontaneous miscarriage.
Side effects of Clomiphene therapy
Treatment with Clomiphene is safe. Side effects, if they occur, are mild and rarely require that treatment be discontinued.
The commonest side effect which occurs in ten per cent of women is the symptom of ‘hot flushes’. Other less common side effects include nausea
and vomiting, abdominal distension and, discomfort, breast discomfort, headaches, mild depression, fatigue, irritability, and very occasionally blurring of vision.
There may also be moderate pelvic pain caused by enlargement of the ovaries. If this happens, treatment is stopped until the ovaries have returned to their normal size. There is a small chance of over stimulation resulting in Ovarian Hyperstimilation Syndrome (OHS).
If visual disturbance or severe headaches or migraines occur the treatment should be discontinued.
A very small increase in the risk of developing ovarian cancer after prolonged treatment with Clomiphene was reported in a few earlier studies, but later studies didn’t show any increased risk. This issue remains a major source of controversy.
If you have any questions
Please contact Jasmine Ward on the number below or contact your own GP.
