CU ARM participates in a study to determine which fertility medication is preferable for treating women with irregular cycles
When I began my infertility training back in 1981, there were only two medication options for inducing ovulation in infertile women – Clomid (clomiphene citrate) and Pergonal, which is a combination of follicle stimulating hormone (FSH) and luteinizing hormone (LH).
Clomid is inexpensive, with a fairly low chance of complications, except for 10 percent chance of twins, and a reasonable side effect profile, mostly hot flashes or moodiness. In the early days we did little monitoring of Clomid cycles, although we knew that Clomid may sometimes thin out a women’s (previously normal) lining, making conception less likely.
If Clomid didn’t work, there was the option of Pergonal injections, which have now been succeeded by Follistim, Gonal F, or mixtures such as Menopur. These are purified versions of FSH and/or LH. The downside is the cost of the medications (typically $1,000 or more per cycle), the need for 8 to 10 days of injections, the need for ultrasound and blood monitoring, and medical risks. These involve multiples, even triplets occasionally, and ovarian enlargement. Pregnancy rates are higher than Clomid ovulation cycles, typically about 25 percent per cycle.
Nowadays, we have a viable third option, an oral medication letrozole (Femara) which works in a way similar to Clomid, but may have better pregnancy rates because it has less of a tendency to thin out the uterine lining or make a woman’s cervical mucus inhospitable to sperm. In small studies, pregnancy rates were improved and side effects reduced compared to Clomid, although it is more expensive.
At UCARM, we are currently involved in a multicenter study comparing Clomid and letrozole for women with irregular cycles, hoping to determine which is preferable. We also are studying couples with unexplained infertility, comparing Clomid, letrozole and injectable medications in a random fashion (couples will not be able to choose which medication they receive). Intrauterine inseminations are used for these cycles. The treatments are provided at no cost.
Hopefully, we will have even better information to counsel patients with infertility in the future.