الفهرس 
ENDOMETRIUMOnly 14 pages are availabe for public view
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Abstract
Successful implantation during In-vitro fertilization and embryo transfer depends on many factors including embryo quality and uterine receptivity. In recent years attempts have been made to simplify In-vitro fertilization treatment and improve pregnancy rate by the use of gonadotrophin releasing hormone agonists.
A lot of attention has recently centered on the receptivity of the endometrium to the growing blastula. High-resolution ultrasonography is currently the imaging modality of choice, but measurement of endometrial thickness is only associated with successful treatment outcome if ovarian stimulation includes gonadotrophins. However, the ultrasonographic texture of the endometrium may have a greater prognostic value for implantation. The current literature is relatively unanimous that a ”triple” layered appearance of the uterus is associated with a 23 - 42% pregnancy rate and that endometrium is unreceptive when iso - or hyperechoic compared with myometrium.
Although it is well known that there are multiple factors which influence successful implantation, there is much debate regarding the relationship of endometrial thickness and morphology to successful implantation in In-vitro fertilization programs. Many teams have reported significant correlations between pregnancy rate and endometrial thickness and morphology as defined by ultrasonography, while others have failed to demonstrate such relationships.
Recently, the measurement of impedance to uterine artery blood flow in In-vitro fertilization cycles has provided an indirect estimation of endometrial receptivity. The impedance of blood flow through the uterine arteries may be expressed as the pulsatility index. It may be classified as low, medium and high in the ranges 0.00-1.99, 2.00-2.99 and >3 respectively. Many teams have reported a significant decrease in pulsatility index in patients whom pregnancy follows In-vitro fertilization, whereas others have failed to show such modifications of pulsatility index in cases of embryo implantation.
However, the implantation potential of good quality embryos remains low during In-vitro fertilization/embryo transfer treatment, despite advances in ovarian stimulation regimes and the methods of assisted fertilization and improved culture conditions. It needs further studies to detect any factor affecting the rate of implantation.
CONCLUSION
• High pregnancy rate with triple layered endometrium in comparison to other endometrial patterns.
• Thin endometrium (less than 7 mm) is usually associated with failure of implantation.
• PI less than 3 is needed to have a successful implantation.
• RI less than 0.76 is needed to have a good prediction of implantation.
• The Doppler parameters PI & RI of uterine artery are significantly different between pregnant & non pregnant patients.