Ovarian follicle, Gray's Anatomy

Recombinant gonadotropin medications used to stimulate ovarian follicle growth approved for usage in the United States are:

  • Gonal-F®
  • Follistim®

Recombinant technology is used to create Gonal-F® and Follistim®. Although the FSH in these drugs is identical in structure and function to naturally occurring human FSH, it is not obtained from human urine. Recombinant DNA technology allows scientists to generate large, pure batches of FSH. Recombinant FSH preparations represent about 95% of the FSH prescriptions used in the United States for treating infertility.

Advantages of the recombinant gonadotropins over the urinary-derived drugs include, and are not limited to:

  • Higher purity
  • Greater batch-to-batch consistency
  • Potentially lower incidence of injection site reactions
  • Potentially greater chance of achieving a clinical pregnancy, according to some published studies
  • Greater cost effectiveness
  • Subcutaneous administration
  • No risk of urine-based infectious contamination

Gonal-F is available in both individual ampules and multi-dose vials, while Follistim comes in individual vials. The dosages prescribed, and the stimulation protocol used for you, must be highly individualized/personalized, as mentioned above for the menotropins. The risks of the recombinant FSH medications are the same as those listed for the urinary-derived stimulation medications (except they don't have the potential for transmission of urine-based infectious and contaminant materials).

Ultrasound and estradiol measurements are used to monitor the development of the follicles. Patients must visit their clinic's office several times during their stimulation for these tests. When the follicles measure 18 mm in mean diameter, and the estradiol levels are appropriate, ovulation is triggered by the use of recombinant Ovidrel (recombinant LH) or hCG.

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