In contrast to oral fertility medications (Clomid) which stimulate the pituitary gland to release more hormones, gonadotropins are injectable hormone medications that directly stimulate the ovaries to produce multiple follicles (eggs).
Gonadotropins are obtained from 2 sources:
1. Highly purified products from human (urine) sources – human menopausal gonadotropins (hMG).
- contain FSH and various amounts of LH
- Available in vials that require reconstitution prior to injection
- Bravelle, Menopur
2. Genetically engineered (recombinant) products – recombinant FSH (rFSH)
- Contain FSH only
- Injected with a pen device
- Follistim, Gonal-F
Another gonadotropin – human chorionic gonadotropin (hCG), is used to mature the eggs and trigger their release at the time of ovulation. HCG is also obtained from either human sources (Pregnyl, Novarel) or engineered recombinant products (Ovidrel).
These medications are usually self administered, subcutaneous injections into the abdomen.
Gonadotropin treatment cycles should be monitored by a trained fertility physician. Monitoring involves bloodwork and ultrasounds to help guide medication dosing, length of treatment, timing of ovulation and to minimize potential side effects and risks.
Timed intercourse or intrauterine insemination usually follows a gonadotropin treatment cycle.
Side effects of Gonadotropins:
- Multiple pregnancy – up to 30%, mostly twins.
- Ovarian hyperstimulation syndrome (OHSS) – ovarian enlargement with multiple cysts in association with other symptoms such as nausea, vomiting, diarrhea, weight gain, bloating and abdominal pain. Mild OHSS occurs in up to 20%, severe OHSS 1-2%.
- Ovarian torsion –twisting of ovaries, may require surgery.