Infertility Medications 101

Learn more about popular medications used to treat infertility. We talk with Dr Alex Quaas, an associate physician with Reproductive Partners San Diego and a clinical assistant professor at the University of California San Diego, about the basics of infertility medications.

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Basic Overview of the Menstrual Cycle and Conception
- During the first days of a normal menstrual cycle, estrogen (hormone) levels are low and your pituitary gland produces follicle-stimulating hormone (FSH) in response to these low estrogen levels. As FSH levels rise, one main follicle (a small cyst that houses an egg) grows and releases estrogen. This will trigger the release of an egg later in the cycle from that follicle.
- 2 halves of the menstrual cycle:
  1. Follicular phase – estrogen driven
  2. luteal phase- progesterone driven
Oral Medications
- Most common
  - clomiphene citrate -Selective estrogen receptor modulator (SERM)
  - letrozole- aromatase inhibitor
  - metformin- insulin sensitizing agents

- How they work
  - Clomiphene citrate and letrozole work by either lowering estrogen levels or by making the brain think they are low. Low estrogen levels tell the pituitary gland to produce FSH, which helps egg follicles grow and release an egg.
    1. Clomiphene citrate works by helping cells resist estrogen. Increases endogenous FSH.
      1. Is often the preferred oral medication for unexplained infertility.
    2. Letrozole work by blocking certain kinds of hormones (androgens) from changing to estrogen
      1. Is often the preferred oral medication for polycystic ovary syndrome PCOS

- - Metformin
    1. No longer a first line fertility medication. Used as an adjunct.
    2. Primarily used with patients who don’t ovulate regularly because of polycystic ovary syndrome (PCOS).
    3. Can be used alone or with clomiphene citrate or letrozole.
- What type of monitoring should be used for patients taking these medications?
- How effective are these medications at helping patients get pregnant?
- What are the risks for patients taking clomiphene citrate and letrozole?
  - Multiple pregnancy?
    1. Higher order multiples: 1% or less
    2. Twins: 5% (The natural rate of 1-2%.)
  - Cancer?
  - Birth defects?

In Vitro Fertilization (IVF) Cycle
- Protocol for a typical IVF cycle
  - 1st part: Downregulation of the ovaries.
    1. Synchronize the egg production of the ovaries so there is no dominate follicle.
  - 2nd part: Stimulation of the ovaries to have multiple follicles grow.
  - 3rd part: Prevention of premature ovulation.
  - 4th part: Ovulation trigger before the egg retrieval.

- The exact drug and dosage used depends on the patients age, diagnosis, and the stimulation protocol prescribed by the reproductive endocrinologist.
- Gonadotropins
  - Purpose: Stimulation phase
  - How are they administered?
  - What type of monitoring should be used for patients taking these medications?
- Gonadotropin releasing hormone (GnRH) analogs (antagonists and agonists)
  - Purpose: prevent premature ovulation
  - How are they administered?
  - What type of monitoring should be used for patients taking these medications?
- Human chorionic gonadotropin (hCG) glycol protein
  - Purpose: to trigger ovulation
  - How are they administered?
- Other medications that can be used in an IVF cycle
- Risks
  - Ovarian hyperstimulation syndrome (OHSS)
  - Risks of retrieval procedure
    - most common is bleeding-less than 1%
    - infection-even less risk
- Multiple pregnancy?
- Cancer?
- Birth Defects