Evaluation of endometrial and sub-endometrial vascularity by transvaginal 3D Power Doppler in prediction of pregnancy outcome in intracytoplasmic sperm injection cycles

Abstract

Objective:
Successful implantation depends on a close interaction between a blastocyst and endometrial
receptivity. Endometrial vascularity is of a prime importance for endometrial receptivity and
embryo transfer.
The aim of this study is to evaluate the role of endometrial and sub-endometrial blood flow
measured by three-dimensional Power Doppler ultrasound on the day of oocyte retrieval in
predicting pregnancy following intracytoplasmic sperm injection ( ICSI ) cycles.
Patients & Methods:
This prospective study included 100 infertile women who underwent a first ( ICSI ) at Minia
University Hospital and Nile Infertility Center, using a Gn-RH long protocol with stimulation by
a recombinant FSH ( r-FSH ) from July 2019 to June 2020. Endometrial and sub-endometrial
blood flow were measured using 3D Power Doppler ultrasound on the day of oocyte retrieval.
The 3D Power Doppler indices – vascularization index ( VI ), flow index
( FI ) and vascularization flow index ( VFI ) were obtained and compared between the pregnant
and non-pregnant groups.
The primary outcome was clinical pregnancy defined as the presence of intra-uterine gestational
sac 4 weeks after embryo transfer. The secondary outcomes were chemical pregnancy, total rFSH dosage and duration of gonadotropin induction.
Results:
There were no statistically significant differences in the clinical characteristics including maternal
age, duration and type of infertility, body mass index ( BMI ), basal hormonal profile ( FSH, LH,
E₂ levels ), total r-FSH dosage, number of retrieved oocytes, endometrial thickness or volume and
number of good quality embryos between pregnant and non-pregnant groups ( P < 0.05 for each ).
Pregnant women had higher endometrial VI, FI and VFI indices and predictive values than the
non-pregnant women ( 0.93. 12.9, 0.14 respectively, P > 0.01 ).
By contrast, no statistically significant differences in the sub-endometrial ( VI, FI and VFI )
indices were observed between the pregnant and non-pregnant groups
( P < 0.05 for each ). In comparing the diagnostic indices and predictive values of the 3D Power
Doppler ultrasound parameters of endometrial blood flow in predicting pregnancy in ICSI cycles,
the FI at a cut-off value < 12.9 had the highest values ( sensitivity 89.7 %, specificity 81.7 %,
PPV 76.1 %, NPV 92.5 % and diagnostic accuracy 85 % ) compared to VI ( sensitivity 76.9 %,
specificity 75.4 %, PPV 66.6 %, NPV 83.6 % and diagnostic accuracy 76 % ) and VFI (
sensitivity 66.7 %, specificity 73.8 %, PPV 61.9 %, NPV 77.6 % and diagnostic accuracy 71 % ).
Conclusion: The 3D Power Doppler ultrasound is a useful, effective and non-invasive tool for
assessing endometrial blood flow in ( ICSI ) cycles. On comparing the diagnostic indices and
predictive values of 3D Power Doppler ultrasound parameters of endometrial and subendometrial blood flow, good endometrial blood flow on the day of oocyte retrieval was a good
predictor of pregnancy in ( ICSI ) cycle. In addition, no correlation was observed between subendometrial blood flow and pregnancy.