Background: To evaluate the effectiveness of intrauterine injection of recombinant human chorionic gonadotropin (rhCG) before embryo transfer (ET). Materials and Methods: In this randomized placebocontrolled clinical trial, a total number of 182 infertile patients undergoing their first in vitro fertilization/intracytoplasmic sperm injection (IVF-ICSI) were randomly assigned to receive 250 μg i...

Embryos have evolved a remarkable capacity to find implantation site. The impressive navigation ability of natural blastocysts may rely on highly sensitive signals arising from embryos and specialized signal processing strategies in the endometrium. Navigation capabilities may be compromised in ICSI embryos because of altered biochemical signaling. The design and delivery of artificial blastocy...

Background: Regulation of gene expression in mammalian embryos is not completely known. Pre-implantation embryos need maternal RNA and proteins synthesized during oogenesis, to regulate development before mater-embryo transition, as the grown oocyte and the 1-cell zygote are transcriptionally silent. There are some oocyte-specific genes called maternal effect genes which may account for this ea...

Background: Clinical infertility is defined as the inability to become pregnant after 12 months of unprotected intercourse. Worldwide, more than 80 million couples suffer from infertility;the majority of this population are residents of developing countries. In vitro fertilization (IVF) is the most successful of the infertility treatments, and for many people is the last possibility for pregnan...

Approximately 390 literature references (through spring 1986) were reviewed for mammalian whole embryo culture procedures, with particular attention to the development of those cultures as systems for teratogenicity testing. The existing procedures could be conveniently divided into three groups, which are defined by the periods of embryogenesis that they embrace: preimplantation, peri-implanta...

Lefty/Ebaf polypeptides, novel members of the TGF-beta superfamily, are involved in endometrial differentiation and embryo implantation. Recently, we showed that, during undisturbed estrous cycle, lefty is present in mouse uterine horn primarily in a precursor form. Here, we show that decidual differentiation of endometrial stroma leads to increased lefty (approximately 3.1- to 3.6-fold in vivo...

Embryo culture can serve as a strong diagnostic tool, yielding useful information regarding the implantation potential of the human embryo. The information thus gained is useful for quality control of the embryology laboratory, success rates of the IVF/intracytoplasmic sperm injection (ICSI) programme, and counselling of the couple following failed cycles. Zygotes can be scored and zygote quali...

The mechanisms that mediate implantation of the human embryo remain poorly understood and represent a fundamental problem in reproductive biology. Candidate molecules that mediate and facilitate implantation have been identified in animal studies, and include heparin binding epidermal growth factor. Here we demonstrate a potential function for the transmembrane form of heparin-binding epidermal...

Implantation is a process in which a developing embryo, moving as a blastocyst [5] through a uterus [6], makes contact with the uterine wall and remains attached to it until birth. The lining of the uterus [6] (endometrium [7]) prepares for the developing blastocyst [5] to attach to it via many internal changes. Without these changes implantation [8] will not occur, and the embryo sloughs off d...

Implantation is arguably the most critical stage in the establishment of pregnancy. In humans, it has been estimated that between 30% and 70% of conceptuses are lost before or at the time of implantation, without women being aware that they were pregnant. Of these losses, half are probably a consequence of genetic defects in the conceptus. The etiology of the remaining losses is unknown. In hum...