Luteinizing hormone and human chorionic gonadotropin: a review of their varied clinical applications in assisted reproductive technology

Abstract

Luteinizing hormone (LH) and human chorionic gonadotropin (hCG) are often viewed as interchangeable from a functional standpoint because they are highly homologous members of the same glycoprotein hormone family that share a common α-subunit and receptor. However, technological advances yielding highly purified and recombinant gonadotropin preparations have revealed that LH and hCG fulfill different roles, both endogenously and when administered exogenously. These differences are becoming more apparent as the individual hormones are incorporated into the treatment of infertility – a therapeutic area that is continually advancing with the introduction of new agents and emerging clinical trial data. This review examines the unique attributes of LH and hCG that drive their distinctive applications in the treatment of female infertility.

Keywords:

• female infertility
• follicular maturation
• glycoprotein hormones
• human menopausal gonadotropins
• luteal support
• ovarian stimulation

Financial & competing interests disclosure

This work was supported by Ferring Pharmaceuticals Inc. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. Writing assistance was utilized in the production of this manuscript, provided by C Murcia and JS McCollam of The JB Ashtin Group, Inc. and Kimberly Brooks of SciFluent.

Key issues

• Technological advances have allowed for parsing out the distinct physiological and therapeutic roles of luteinizing hormone (LH) and human chorionic gonadotropin (hCG).

• With the introduction of highly purified and recombinant gonadotropin products, clinicians are better able to tailor assisted reproductive technology protocols to meet patient needs and improve the likelihood of a positive outcome.

• Sources of exogenous LH activity are not equivalent and endogenous LH cannot be considered interchangeable with exogenous hCG.

• Clinical context dictates the appropriate use of LH activity supplementation for ovarian stimulation, triggering of final follicular maturation and luteal support.

• The longer half-life of hCG (vs LH) makes it a more advantageous product in assisted reproductive technology, where the luteal phase needs to be supported. For the same reason, hCG should be used with caution in patients with overresponding ovaries to follicle-stimulating hormone treatment. However, in general, hCG appears to have greater pharmaceutical value because of its broad range of applications.

• New agents and emerging techniques are continuously changing how LH and hCG are applied to the treatment of infertility.

Notes