Ovulation induction by hMG (human menopausal gonadotropin)
This is a powerful and effective drug. hMG (human menopausal gonadotropin) contains both FSH and LH hormones e.g. pergonal, menogon. It is a purified extract from the urine of postmenopausal women. It stimulates the ovaries to produce multiple follicles. It is usually offered in selected cases, e.g. if clomiphene treatment has been unsuccessful and for women whose pituitary glands produce no FSH and LH of their own. The treatment is complex and expensive.
It is given by injection repeatedly over several days in the first half of the cycle. The dose required varies from woman to woman and even the same patient may not respond in the same way from cycle to cycle. There is an increased risk of many eggs being produced in the same cycle. This is why women who are given these drugs need careful monitoring during their treatment cycles.
HMG induces ovulation in about 75-85% of appropriately selected patients.
Despite intensive monitoring, multiple pregnancies occur in about 20% of the treatment cycles. And of that, one-third is triplets or more.
Some women are concerned that the drug causes them to run out of eggs and will go to early menopause. This is not true as in a natural cycle, about 40-60 eggs start to mature but only one mature while the rest die. hMG helps to rescue some of these eggs which would otherwise have died.
A possible association between ovulation induction with hMG and ovarian cancer remains uncertain. Furthermore, the Committee on Safety of Medicines in the United Kingdom has advised that no medical products using urine sourced in a country that has reported cases of human variant CJD (the human form of mad cow disease) be used in the UK.