Abstract
Gonadotropins extracted from the urine of post-menopausal women have traditionally been used to stimulate folliculogenesis in the treatment of infertility and in assisted reproductive technology (ART). Products, such as human menopausal gonadotropin (hMG), consist not only of a mixture of the hormones, follicle-stimulating hormone (FSH), luteinising hormone (LH) and human chorionic gonadotropin (hCG), but also other biologically active contaminants, such as growth factors, binding proteins and prion proteins. The actual amount of molecular LH in hMG preparations varies considerably due to the purification process, thus hCG, mimicking LH action, is added to standardise the product. However, unlike LH, hCG plays a different role during the natural human menstrual cycle. It is secreted by the embryo and placenta, and its main role is to support implantation and pregnancy. More recently, recombinant gonadotropins (r-hFSH and r-hLH) have become available for ART therapies. Recombinant LH contains only LH molecules. In the field of reproduction there has been controversy in recent years over whether r-hLH or hCG should be used for ART. This review examines the existing evidence for molecular and functional differences between LH and hCG and assesses the clinical implications of hCG-supplemented urinary therapy compared with recombinant therapies used for ART.
Highlights
The human gonadotropins, luteinising hormone (LH), follicle-stimulating hormone (FSH) and human chorionic gonadotropin, are complex heterodimeric glycoprotein hormones that each play pivotal, though differing, roles in the female reproductive system
A more recent matched pair study [81] of women receiving either r-hLH/recombinant forms of human FSH (r-hFSH) or human menopausal gonadotropin (hMG) during controlled ovarian stimulation (COS) showed that pregnancy rates per cycle (p = 0.006; p = 0.022) and per embryo transfer (p = 0.025; p = 0.008), and implantation rate per embryo transferred (p
In this review we have described the differences in the structure and function of the gonadotropins LH and human chorionic gonadotropin (hCG), and have discussed how these differences may impact on the clinical outcomes of the use of recombinant or urinary therapies for assisted reproductive technology (ART)
Summary
The human gonadotropins, luteinising hormone (LH), follicle-stimulating hormone (FSH) and human chorionic gonadotropin (hCG), are complex heterodimeric glycoprotein hormones that each play pivotal, though differing, roles in the female reproductive system. While in vitro studies have reported that EGF increases cumulus cell numbers and oocyte maturation [9], the exogenous EGF in hMG could interfere with the normal process of cell proliferation and differentiation in endometrial cells by synergising with other growth factors and replacing the actions of oestradiol It might compete with other EGFlike factors reported to play roles in oocyte development and ovulation [10]. Another potential contaminant of hMG, insulin-like growth factor (IGF)-binding protein-7 regulates cellular proliferation, adhesion, and angiogenesis, and may suppress oestrogen production by granulosa cells [11]. The high levels of hCG contained in hMG, together with its longer half-life, may lead to an undesirable accumulation of LH-like bioactivity with possible premature luteinisation and reduced fertilisation rates [35] or to a reduced response as a result of LH/hCG receptor desensitisation.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
