More and more couples who are unable to have children are turning to fertility drugs today. As with many drugs, there are two schools of thought. Some say fertility drugs have been used safely and successfully. Others claim they "supercharge" women's' ovaries, causing unnatural reactions that result in unplanned, unsafe multiple births.

Here is a quick look at the more popular drugs and how they work:

Clomiphene: This pill, which is taken five days a month, stimulates hormones in the brain that tell the ovaries to get eggs ready and release them. Between 70 to 90 percent of women will ovulate. Of those, 20 to 60 will get pregnant. Side effects include mood swings, swelling, stomach pain, breast tenderness, nausea and vomiting. Cost: $30 for one cycle.

Human Menopausal Gonadotropin (hMG): Injections - given for seven to 12 days each month - that make women develop egg follicles and then release eggs. Usually takes three to six cycles and success rates and symptoms are similar to that of Clomiphene. In rare cases, women have developed hyperstimulated ovaries, a fatal condition. Cost: $2,000 to $5,000 a cycle (includes drugs, office visits and tests).

Bromocriptine: An oral or vaginal pill that reduces the production of prolactin, the hormones that reduces estrogen levels and inhibits ovulation. Taken two to three times a day, it can cause nausea, dizziness and headaches. About 90 percent of women ovulate and 65 to 85 percent of those will get pregnant. Cost: $75 to $112 a month.