Fertility Drugs and IUI

Fertility Drugs and IUI

Intrauterine insemination (IUI) can be performed naturally: Sperm is prepared and delivered directly into a woman’s uterus when she is ovulating. However, IUI is often done in conjunction with medications to stimulate her body to develop multiple eggs. This process goes by many names, including superovulation, controlled ovarian hyperstimulation, and ovulation induction by hormone therapy.

Several studies have found that, for couples with unexplained infertility, IUI done along with superovulation offers a greater chance of pregnancy than IUI done in “natural” menstrual cycles. For folks with unexplained infertility, without superovulation, IUI produces similar pregnancy rates as well-timed intercourse.

One study, conducted by researchers at the University of Rochester Medical Center in the late 1990s, found that superovulation combined with IUI was associated with a three-fold higher chance of pregnancy than no treatment at all and a two-fold higher chance of pregnancy than either IUI or superovulation alone. Couples facing infertility who used both superovulation and IUI had a 33 percent pregnancy rate, compared with infertile couples who used no fertility treatments, who had a 10 percent pregnancy rate.

The Medication Options

The drugs that are given include clomophine citrate (such as Clomid), aromatase inhibitors (such as letrozole), and gonadotropins (such as hMG). Studies have found that clomophine citrate and letrozole have comparable pregnancy rates. Insemination with gonadotropins, however, provides better pregnancy rates (around 15 percent per cycle for couples with unexplained infertility) than insemination with clomiphene (around 5 to 10 percent per cycle). That’s because gonadotropins usually stimulate more mature eggs to develop.

Women usually begin taking these medications early in the menstrual cycle, on the second, third, fourth, or fifth day after they get their periods.

Soon after that, a woman’s doctor will begin watching for signs of ovulation, to know when to schedule the IUI. However, sometimes when women are given these medications to stimulate ovulation, it can prevent the natural LH surge that triggers ovulation from occurring. If this is the case, the woman will receive (or give herself) an injection of human chorionic gonadrotropin (hCG) in the evening. That shot will trigger ovulation within 36 to 40 hours. The IUI is usually scheduled around 36 hours after the shot.

Risks

All ovulation medications have the increased risk of multiples: twins, triplets, and more. However, studies have found that in women with infertility caused by mild endometriosis, the combination of IUI and superovulation with gonadotropins had a much higher birth rate than in women who received no fertility treatment.

Although there have been concerns of these medications causing birth defects, according to the American Society for Reproductive Medicine, “clomiphene citrate and gonadotropins are not associated with an increased risk of birth defects.” However, there is concern that letrozole may be associated with an increased risk of birth defects.

Also, many fear a connection between these medications and an increased risk of cancer in women. Recent studies have not found a link between superovulation and ovarian cancer. However, in 2006, researchers in Israel found that women taking clomiphene citrate had an elevated risk of breast cancer.