 Hello friends, I'm Dr. Gita Shah and I will be talking about the role of color Doppler in endometrial receptivity and uterine scoring before embryo transfer. Assisted reproductive technology is a very important tool for management of infertility. And implantation presents the greatest challenge to the ART specialist because less than one third of embryos replaced in the uterus complete implantation. A successful human implantation is a very synchronized process with a close interaction between embryo development and endometrial differentiation. We now have a better understanding of the physiology of uterus ovaries at endometrium during various phases of the menstrual cycle, ovulation induction as well as normal pregnancy due to improved ultrasound imaging, color flow measurements, blood flow in the uterus and vascularization of the endometrium. Let us quickly brush through the vascular anatomy of uterine artery. It is a branch of the internal iliac artery and it enters the uterus at the corpus cervical junction. This is the site where we do the Doppler examination and the uterine artery and nastmosis with the opposite uterine artery where the arcuate arteries which run just beneath the myometrium and they give rise to radial arteries which travel perpendicularly through the myometrium up to the endometrial surface where they give rise to two branches, one the straight artery which supplies the basal layer of the endometrium and the coil spiral arteries which progress through into the endometrial cavity and it is these spiral arteries which respond to the circulating hormones and play a very important role in the implantation process. The endometrium also undergoes a lot of changes around the mid follicular stage as well as in the early luteal stage where the glands become very coiled and prominent with a lot of fluid and that is what is reflected in the ultrasound appearance as well. So what are the normal endometrial changes that we see on ultrasound fortunately the endometrium shows us some very signature appearance and in fact it is possible to predict the day of the menstrual cycle from the image of the endometrium on ultrasound. The Casper's classification of endometrium shows in the early proliferative stage you just see a single line here the endometrial cavity and in the early proliferative phase say around day 9 or 10 you see a very hazy triple layer pattern and the mid follicular phase you see a very well defined triple layer pattern or a five line pattern and in the mid luteal phase you see a bright echogenic thick endometrium. The endometrial vascularity zones are also described as per the vessels seen in the different layers of the endometrium. Zone 1 is when we see vascularity in the myometrium just surrounding the endometrium. Zone 2 is when we see vascularity in hyperechoic endometrial edge. Zone 3 is when we see the vascularity in the internal endometrial hypoechoic zone and zone 4 when we see the vascularity in the endometrial cavity. The perfusion in the endometrial cavity increases in response to circulating estrogen and pridestrom and the perfusion decreases with the peri ovulatory fall in estrogen. The lowest PI is seen around day 21 which is the time of implantation. So the endometrial change is that we see in a normal menstrual cycle. In the early proliferative stage you see the vascularity up in the myometrium and the resistance also progressively decreases. In the mid follicular stage around day 12 you see the vascularity up to zone 2 with a further reduction in the resistance with the RI of about 0.6 and then around the follicular stage or around the ovulation day you see the blood flow rate up to the zone 4 as well with the RI of about 0.4. Even the uterine artery undergoes changes around the mid follicular stage, the uterine artery on the dominant side, the ovary with the dominant follicle shows reduced resistance with the PI of around 2 and on the non-dominant side a high PI of about 3 and this low resistance persists till the luteal phase and then it rises again when there is no pregnancy. The normal endometrial in the luteal phase you see a multifocal flow within the endometrium with a very low resistance with the RI of about 0.4 and again in the late luteal phase just prior to menstruation you don't see any vascularity within the endometrium. The endometrial receptivity can also be studied by transvaginal color Doppler and 3D power Doppler and angio where the density of the vessels can be studied within the endometrium and with various parameters like the vascularization index and flow index. The uterine blood flow in infertile women as we can see here is very much reduced with a very high resistance of about 0.9 as compared to low resistance in normal fertile women of about 0.8 and the spectral wave form showing absent endostealic flow. Even the spiral artery shows absent endostealic flow so the uterine scoring system which was first described by Applebaum in 1995 also known as the uterine biophysical profile score can be used and there are seven parameters which are studied the endometrial thickness. The scores go up as the endometrial thickness increases but again when it the thickness is very very high as like more than 14 millimeters the score again goes down. Endometrial layering is very important with no layering score of 0 and when we see a well defined good triple layer score of 3 endometrial peristalsis when we see a score of 3 homogenous myometrial ecogeneity again a very high score, uterine artery PI of 2.5 to 3 again a zero score and a low PI of less than 2 score of 2. When we see endometrial flow in zone 3 that is a multifocal flow that is a high score of 5 but a very scarce flow is a score of 2. When we see myometrial flow on grayscale that is a score of 2 and when we see a very high score almost a total score of 20 there is a 100 percent chance of pregnancy as described by applebomb and when there is a score of 70 to 90 80 percent chance of pregnancy and as the scores go down there is a reduced chance of pregnancy with absent endometrial flow zero chance of pregnancy. There are various studies that corroborate these findings where the RI of the uterine arteries when it was high these patients did not get pregnant and patients with low uterine artery PI on the day of embryo transfer there was a more positive outcome and they were more likely to conceive inadequate vascular penetration of the endometrial blood flow prior to transfer was associated with an unfavorable outcome and a progressive decrease in the PI of uterine arteries was demonstrated in the second half of menstrual cycle in successful IVF pregnancies. So in conclusion transvaginal color power Doppler as well as 3D power Doppler evaluation of the endometrial and some endometrial flow is a very simple non-invasive effective method to determine endometrial receptivity a high degree of endometrial perfusion that is demonstrated by color or power Doppler indicates a more receptive endometrium. Uterine scoring will help to perform embryo transfers in only favorable uterine and cancel or postpone those cycles in which per uterine score is demonstrated. Thank you very much for your attention.