Letrozole for Superovulation
Letrozole is an oral fertility medication. It can be used to induce ovulation in women who don’t ovulate, or to produce multiple eggs in women who already ovulate on their own. It is an alternative medication for those who have experienced significant side effects with clomiphene citrate (hot flashes, mood swings, thinning of the endometrium). The two medications are comparable in terms of ovulation rates, pregnancy rates and risk of multiple pregnancies.
Letrozole may have harmful effects upon a developing pregnancy, and a negative blood pregnancy test is required before starting each cycle of medication. Depending upon your situation, the doctor may request that you get a baseline ultrasound performed before you start therapy. If so, call the office (913)780-4300 when your period begins. The ultrasound is generally scheduled on the second or third day of your period.
You will take two tablets (5 mg total) of letrozole daily, starting on Cycle Day 3 (the first day of menses is Cycle Day 1) and ending on Cycle Day 7. You can take the two pills together, and the time of day is not important (just be consistent for the five days).
If you are timing an insemination (IUI) by ultrasound, call the office by Cycle Day 7 to schedule the sonogram on Cycle Day 12. Once the follicles have grown to 18mm or larger, you will be given an injection of hCG to trigger ovulation and the IUI will be scheduled the following day. An ultrasound is recommended during your first treatment cycle to check the effectiveness of the medications.
If you are timing the IUI by ovulation predictor kit, you should start checking your urine early in the morning with the kit on Cycle Day 11. Most women will have a positive test around Cycle Day 13 or 14. Once the test is positive, call the clinic to schedule the IUI. Semen collection is scheduled in the clinic the following day and the IUI is usually performed approximately 1 – 2 hours later. If you have a positive surge on a weekend you will need to leave a message early in the morning no later than 9:00 am so that we may call you back to schedule your IUI for the following day. You may collect the specimen at home if you live less than 60 minutes from the office and have a sterile container that we have provided for you. If your test has not turned positive by Cycle Day 15, call the clinic for assistance.
There is a 5-10% risk of twins with the use of letrozole; the risk of triplets or higher order pregnancies is <1%. Side effects may include hot flashes, headaches, stomach upset, weakness and back pain. Ovarian cysts can appear with the use of letrozole, which may cause pelvic pressure or pain with intercourse or exertion. They are usually self-limited and resolve without any further treatment except withholding the next cycle of medication.