If you have been trying for a while to get pregnant, your ob/gyn may give you a prescription for Clomid or Serophene. Both of these drugs contain clomiphene. But that still doesn't answer the key question: why did my doctor tell me to take this?

Clomiphene was actually developed as birth control because over time it causes the uterine lining to thin. That takes months, so don't run back to your doctor and accuse him or her of trying to prevent you from getting pregnant! The other effect clomiphene has is that it regulates ovulation. If you have irregular ovulation or PCOS, clomiphene pretty reliably will cause you to ovulate. Simply ovulating more frequently and appropriately timing intercourse may be all you need to get pregnant. If you already ovulate, clomiphene will likely cause you to develop multiple follicles, resulting in multiple eggs, and the hope is that you will have a higher likelihood of one of those eggs fertilizing.

Clomiphene is typically taken twice a day on days 5-9 of your cycle. There are studies looking at different dosing schedules, such as days 2-6 or 3-7, to allow for the uterine lining to recover, if it was negatively affected. Generally, in the first few months, that is not a problem.

It works by tricking the brain into thinking that there is not enough estrogen, so more FSH and LH are produced, resulting in an increase in estrogen. The increased hormones cause more follicles to develop in the ovaries. At the same time, that is the cause of the side effects, too. The extra estrogen can cause hot flashes, headaches, ovarian cysts or enlargement, breast tenderness, and mood swings. It can also create a "hostile cervical mucus" that negatively impacts sperm, which is why clomiphene treatment is often combined with intrauterine insemination to bypass the cervix. And clomiphene can result in multiple births--that risk is about 10%, usually twins.

The problem with clomiphene is that since it is cheap and easy to prescribe, some women are not monitored while taking it. They may take it for 6 months unsupervised, and still not get pregnant. It is important to take it with monitoring for follicular development, and ideally, with ovulation triggered by an injection of HCG to maximize the chance for pregnancy. Many doctors draw the line at 5 follicles--if you develop more than 5 follicles, they will not give you the HCG shot because you run a higher risk of multiple fertilizations. Most reproductive endocrinologists do not prescribe clomiphene longer than three months before moving on to something else. Pregnancy success rates with clomiphene are low, about 10-15% per cycle, and time is a consideration. If your problem is that you do not ovulate, clomiphene will probably make you ovulate, and that alone improves your chances for pregnancy. If you already ovulate, the multiple follicles that result will also improve your chances.

Discuss your options with your doctor. If you're young and anovulatory, clomiphene is a reasonable place to start, but make sure your get supervision of your follicular development. If you're over 35, get yourself to a reproductive endocrinologist before taking clomiphene because there may be other reasons that you're not getting pregnant, and clomiphene may be a waste of time. But as always, keep your hopes up that this month is your lucky month!