Endocrinology Profile in Patients Undergoing Clomiphene, Letrozole, and Combination Clomiphene and Letrozole Cycles

After the initial physician consultation and investigations have been completed, the treatment options will be reviewed with the patient. If the patient chooses ovulation induction with an oral medication, then she will be offered participation in the study.

If she chooses to participate, the patient will then undergo ovulation induction with either clomiphene, letrozole, or a combination of both medications. The patient will be randomized to the order that each medication regimen will be started. Prior to starting each treatment cycle, a serum beta-hCG (serum beta-hCG < 5IU/L) or urine pregnancy test will be performed to rule out pregnancy.

During one treatment cycle, the patient will take 100mg clomiphene orally from cycle days 3-7. This dose is routinely used for ovulation induction in the investigators clinic. Blood work including an estradiol (E2), FSH, inhibin B and LH will be obtained on cycle days 3, 7, and 9. As these lab tests are routinely performed in the investigators REI laboratory, there will be no additional cost to the patient. A baseline follicle count by ultrasound during each treatment cycle will be measured on cycle day 3, and then again on cycle day 12, 13, or 14, depending on the cycle length until the lead follicle is 18mm or greater. Once at least one follicle has reached this mature size, an Ovidrel trigger (250 mcg hCG subcutaneously) will be administered to initiate ovulation. The patient will have an intrauterine insemination (IUI) 36 hours after Ovidrel injection. These procedures are the current standard of care in the investigators fertility center for patients with unexplained infertility.

Ovulation during each treatment cycle will also be confirmed with a serum progesterone measurement >3 nmol/L on cycle day 20-25. This blood test is not always performed, but is a common way to assess ovulation.

If the patient ovulated, a pregnancy test will be performed approximately 2 weeks later. If pregnancy has not occurred, the next medication would be attempted after the patient has a period.