Doppler of uterine, spiral a & endometyrial blood flow studies in predictioin of implantion and pregancy rate in ART

 

Q.1A)  Which kind of Doppler( 2 D or 3 D)  is most predictable  2) Which vessel is to be studied ?  Doppler is often used to quantify blood flow , & nutrient supply  in uterus , endometrium in particular. But out of three kind of vessels like uterine artery, vessel is most predictive for implantation rate pregancy rate What we the clinicians  receive informations on studying  the  different Blood flow of vessels  in  uterine  vessels specially in subfertility treatment cycles ? Can we prognosticate ??                                                                                                                                   Q.1: What does   Doppler study of uterine vessels  means to us?? Ans: It reflects the downstream impedance to flow . It is assumed to reflect the endometrial blood flow. It is usually expressed as the pulsatility index (PI) and the resistance index (RI).

Q.2: What is then  PI of a vessel??  PI is calculated as the peak systolic velocity (PSV) minus end-diastolic velocity divided by the mean, whereas RI is the ratio of PSV.

Q.3: ) What is FVW??:-It implies Flow velocity waveforms. FVW in case of uterine arteries are evaluated from the ascending branch of the uterine artery on the right and left side of the cervix in a longitudinal plane before it enters the uterus. The gate of the Doppler is positioned when the vessel with good color signals is identified on the screen. The PI and RI of the uterine arteries are  calculated electronically when three similar, consecutive waveforms of good quality were obtained.

Q. 4:- How do we  know  from the Doppler report page  that the blood flow to placenta or Ut artery is normal & optimal??  Ans:  Good uterine blood flow will be exhibited by low PI or RI . PI & RI of uterine arteries have  been, extensively used both  in obstetric practice as well as gynecological condition . In Gynae conditions  PI, RI are  mostly studied  in ART cycles and correlated with successful IVF outcomes.  

For instance, PI measured on the day of ET is  classified as A) as low, B) medium and C)  high in the ranges of 0-1.99, 2.00-2.99 and >3.00, respectively. It is   reported  that a 35% implantation failure has occurred when PI was >3.0 or 3.3.So a high PI in ut a bears a poor prognosis implantation .

 Q. 5: How important is uterine Doppler flow indices in  ART settings in compared with endometrial thickness and pattern??

?Ans:-  uterine Artery Doppler flow indices have a high negative predictive value and sensitivity (in the ranges of 88-100 %,respectively) and a relatively higher range of positive predictive value and specificity (44-56 % and 13-35%’,respectively) when compared with endometrial thickness and pattern.

Q.6 . What is then , the  take home message on 2-D Uterine artery Doppler studies ?? Ans:- Uterine artery Doppler study may not reflect the actual blood flow to the endometrium as the major compartment of the uterus is the myometrium and there is collateral circulation between uterine and ovarian vessels. Many have demonstrated that  2D Doppler study of uterine vessels is poor reflection of sub endometrial blood flow by 3D power Doppler in both stimulated and natural cycles as endometrial and sub endometrial 3D Doppler flow indices were similar among patients with averaged uterine PI <2.0,2.0-2.99 and >-3.0

 

Q. 7: What is then , the  take home message on endometrial and sub endometrial blood flow by 2D Doppler Endometrial and sub endometrial blood flow examined by color and power Doppler ?  This , in contrast 2-D Uterine artery Doppler studies   was correlated with implantation  rate or pregnancy rates during IVF treatment. As such endometrial blood flow studies and  sub endometrial blood flow are more informative than Ut a Doppler studies.

 

Q. 8:- What about Doppler flow indices of spiral arteries?   Details of implications of Ut artery and endometrial vessels have been quoted in ART practice but how important is  2D Doppler flow indices of spiral arteries such as PI and PSV?? Ans:- Such are not predictive of pregnancy although some researchers observed  significantly lower spiral artery PI in pregnant cycles than nonpregnant cycles .Yang et al used a computer software to measure the area and intensity of color signals present in the endometrium in a longitudinal axis i.e. intraendometrial power Doppler area.(Endometrial Power Doppler Area) significantly higher EDPA was found in pregnant cycles than nonpregnant cycles. Patients EDPA (Endometrial Power Doppler Area )<5 mm had significantly lower pregnancy rate and implantation rate than those with >5 mm.

Q. 9:- How to Grade  the  endometrial  blood:-

Few researchers have already graded endometrial blood flow by the visualization of power Doppler in the quadrants in the fundal region of the transverse plane but could not demonstrate any predictive value of such grading system.

Q. 10:  2-D or 3-D in ART ??  Does all these discussions boils down to the fact that 2D has no value in stimulated cycle or in IVF cycle to predict the success implantaiin rate??  Ans: No. One cant conclude like that., That will be oversimplification of all such discussions. The fact remains that the presence of endometrial and subendometrial blood flow can be indentified easily in 2D Doppler ultrasound. As a matter of fact in such situations ( i.e. absent endometrial and sub endometrial blood flow)  has been shown to be associated with no pregnancy or a significantly lower pregnancy rate.

Q. 11:--What about 3  Doppler ? Ans:- Endometrial and sub endometrial blood flow by 3D Doppler & Endometrial Volume assessment are sometimes used in ART centers .   3D power Doppler ultrasound with the aid of the VOCAL (virtual organ computer Aided Analysis)  measure the endometrial Volume and indices of blood flow within the endometrium .

What is meant by Vascularization index (VI),? Ans:  This  measures the ratio of the number of color vowels, is thought to represent the presence of blood vessels (vascularity) in the endometrium, and this was expressed as a percentage (%) of the endometrial volume. Flow index (FI), The mean power Doppler signal intensity inside the endometrium, is thought to express the average intensity of flow. Vascularization flow index (VFI) is a combination of vascularity and flow intensity.

The subendometrium can be examined through the application of shell imaging which allows the user to generate a vavriable contour that parallels the originally defined surface contour. The  VI, FI and VFI of the subendometrial  region are obtained accordingly.  The intraobserver reliability and intra-observer reliability of endometrial and subendometrial blood flow by 3D power Doppler have been confirmed to be high with all measurements obtaining an intra-class correlation of above 0.9 .