Useful information on the three main types of fertility drugs used to promote ovulation and thus increase the chances of conception, including hMG and Clomiphene.
Fertility drugs work by stimulating hormones in a woman's brain to get an egg ready and release it from her ovaries each month, thus promoting ovulation. Many fertility drugs have been used safely and successfully for more than 30 years. Unlike many other infertility solutions, such as in vitro fertilisation, fertility drugs will not increase the chance of multiple births beyond 5 to 15 percent. The most common fertility drugs include Clomiphene, Human Menopausal Gonadotrophin, and Bromocriptine.
Clomiphene, taken in pill form daily, stimulates the pituitary gland to produce follicle-stimulating hormones, which are the hormones that trigger ovulation. It prompts the ovaries to prepare a number of eggs for ovulation. Once the drug cycle is finished, the hypothalamus gland releases a lutenizing hormone, which instructs the ovaries to release a mature egg from its follicle to the Fallopian Tubes. Women who ovulate irregularly or not at all commonly use Clomiphene. Clomiphene can cause a wide range of side effects, including mood swings, dry cervical mucus, mild ovarian enlargement, stomach pain, breast and ovarian cancer. About 70 to 90 percent of women who take Clomiphene will ovulate, and of those who ovulate, 20 to 60 percent will get pregnant.
Human Menopausal Gonadotropin (hMG) consists of purified follicle stimulating hormone (FSH). When injected into the body, FSH causes a woman to develop egg follicles. After seven to twelve days of shots, the woman receives an injection of human chorionic gonadotropin that stimulates the ovaries to release the egg or eggs it has just developed. HMG is most often given to women with low oestrogen levels who have not responded to Clomiphene. Possible side effects from hMG include abdominal tenderness and weight gain. In rare cases, less than 5 percent of the time, women develop hyper stimulated ovaries, a potentially fatal condition signalled by sudden onset of severe pelvic pain, nausea, vomiting, or weight gain. Due to an excessive number of eggs, the ovaries rapidly swell to several times their size and may leak fluid into the abdominal cavity. Even with careful monitoring, multiple pregnancies and ovarian hyper stimulation can occur. The rate of multiple births is close to 20 percent. About 70 to 90 percent of women who take hGM will ovulate, and of those who ovulate, 20 to 60 percent will get pregnant.
Bromocriptine, which can be taken orally or as a vaginal pill, reduces the pituitary gland's production of the hormone prolactin. Excess prolactin reduces oestrogen levels and inhibits ovulation. Women who take Bromocriptine usually suffer from hyperprolactinemic amenorrhea, which is a condition where ovulation problems are caused by a pituitary adenoma (a benign tumour). Side effects from Bromocriptine include nausea, dizziness, low blood pressure, and headaches. Patients who take the drug vaginally often report fewer side effects. 90 percent of the women who take Bromocriptine will ovulate as long as they continue taking the drug. Of the women who ovulate, 65 to 85 percent will get pregnant.