Ovarian Stimulation, Ooctye Maturation and Fertilization

*Embryology - Theory and Practice*

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10.1016/j.cryobiol.2004.03.002

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**Chapter 2**

**Abstract**

proteomics

**1. Introduction**

half-life and receptor binding affinity [1].

Background Proteins in Human

Pharmaceutical Formulations of

Gonadotropins, including human chorionic gonadotropin (hCG), have been used since and for several decades to treat infertility by ovarian stimulation. hCG is the most important protein for embryogenesis and embryo development and implantation in uterus upon fertilization of oocytes. The hCG used for in-vitro fertilization (IVF) is being extracted from urine of pregnant women, and it does inevitably contains other proteins secreted into urine. The presence of other proteins varies from batch to batch, and it can be significantly high. Due to the fact that many of the proteins identified in these formulations can trigger an allergic reaction, which, in turn, can affect the embryogenesis and prevent embryo implantation, it is very important to check the amount and type of contaminant proteins in pharmaceutical formulations. It was found that the total protein content varied from batch to batch, and a large number of contaminant urinary proteins were

identified in all analyzed samples except for the recombinant product.

**Keywords:** embryogenesis, in-vitro fertilization, human chorionic gonadotropin,

Human chorionic gonadotropin (hCG) is one of the most widely studied markers in embryonic development. It is used as an obstetric marker, and it is often regarded as little more than a signal for maternal recognition of pregnancy. Human chorionic gonadotropin is a member of the dimeric glycoprotein hormone family that also includes FSH, LH, and TSH. The members of this hormone family share a common α subunit and have a unique β subunit to each hormone. Additionally, each hormone shows a different level of glycosylation, which determines circulating

The success of embryo implantation upon IVF and embryo transfer depends on various factors related to the embryo quality and patient's endometrial receptivity. Upon implantation, it is important that the embryo reaches the endometrial cavity during the period of time in which the endometrium is receptive. It has been estimated that 50–75% of lost pregnancies are due to the embryo's implantation failure as described by Tsampalas et al. [2]. Many factors are involved in the implantation

Chorionic Gonadotropin

*Tanja Panić-Janković and Goran Mitulović*

Different Origins
