J. Alphonse

The Aortic Isthmus: A Significant yet Underexplored Watershed of the Fetal Circulation.

The aortic isthmus (AoI) is a unique fetal watershed with a waveform reflecting its complex haemodynamic physiology. The systolic component represents left and right ventricular systolic ejection, and the diastolic component represents comparative downstream vascular impedance between the brachiocephalic and subdiaphragmatic fetal circulations. Several indices have been devised to quantify different components of the waveform, including the pulsatility index, resistance index, isthmic flow index, and recently the isthmic systolic index. There have been promising preliminary studies applying these indices to both cardiac (congenital) and extracardiac pathologies, including intrauterine growth restriction and twin-twin transfusion syndrome. However, the waveforms multifactorial origin has proven to be challenging, and the difficulty in separating various components of the waveform could explain that AoI evaluation does not have a clear clinical utility. Further research is underway to realise the full potential of this vessel in fetal cardiac and haemodynamically compromised pathological conditions. In this review article we outline the physiological origin of this Doppler waveform, describe in detail the various published indices, summarise the published literature to date, and finally outline potential future research and hopefully clinical applications.

The Effect of Ethnicity on 2D and 3D Frontomaxillary Facial Angle Measurement in the First Trimester.

Objectives. To determine the existence and extent of ethnic differences in 2D or 3D fetal frontomaxillary facial angle (FMFA) measurements. Methods. During routine 11–14 weeks nuchal translucency screening undertaken in a private ultrasound practice in Sydney, Australia, 2D images and 3D volumes of the fetal profile were collected from consenting patients. FMFA was measured on a frozen 2D ultrasound image in the appropriate plane and, after a delay of at least 48 hours, was also measured on the reconstructed 3D ultrasound volume offline. Results. Overall 416 patients were included in the study; 220 Caucasian, 108 north Asian, 36 east Asian and 52 south Asian patients. Caucasians had significantly lower median FMFA measurements than Asians in both 2D (2.2°; P < 0.001) and 3D (3.4°; P < 0.001) images. Median 2D measurements were significantly higher than 3D measurements in the Caucasian and south Asian groups (P < 0.001 and P = 0.04), but not in north and east Asian groups (P = 0.08 and P = 0.41). Conclusions. Significant ethnic variations in both 2D and 3D FMFA measurements exist. These differences may indicate the need to establish ethnic-specific reference ranges for both 2D and 3D imaging.

Fetal myocardial performance index in assessment and management of small‐for‐gestational‐age fetus: a cohort and nested case–control study

To assess the clinical utility of the fetal myocardial performance index (MPI) in assessment and management of the small‐for‐gestational‐age (SGA) fetus/growth‐restricted fetus (FGR).

Frontomaxillary facial angle measurement in trisomy 21 and euploid fetuses: two-and three-dimensional assessment during routine first trimester screening

Objective: To assess 2D and 3D frontomaxillary facial angle (FMFA) measurements in euploid and trisomy 21 fetuses. Materials and Methods: Over a 2-year period, women with singleton pregnancies attending a private prenatal screening and diagnosis practice in Sydney, Australia, were invited to participate in this study where 2D images and 3D volumes of the fetal face were collected during routine first trimester screening. In pregnancies where trisomy 21 was confirmed, FMFA measurements were performed in 2D and 3D and compared with those from a euploid cohort. Results: Overall, 250 women carrying euploid and 22 women carrying trisomy 21 fetuses participated. Trisomy 21 fetuses had significantly larger FMFA measurements than euploid fetuses in both 2D and 3D assessments. 95% of 3D and 100% of 2D FMFA measurements for the trisomy 21 fetuses were above the mean FMFA measurement of the euploid fetuses. There was no relationship between increasing crown-rump length and FMFA measurement. Conclusion: 2D and 3D FMFA measurements in trisomy 21 fetuses are statistically greater (p < 0.001) than those in euploid fetuses. This supports FMFA as a possible additional marker for trisomy 21 for first trimester screening.

Use of the Foetal Myocardial Performance Index in monochorionic, diamniotic twin pregnancy: a prospective cohort and nested case-control study

Abstract Aims: Assess clinical utility of the foetal Myocardial Performance Index (MPI) in evaluation and management of monochorionic, diamniotic twin (MCDA) pregnancies. Methods: Prospective cohort of (a) initially uncomplicated MCDA (b) Complicated MCDA, including twin–twin transfusion syndrome (TTTS), selective intrauterine growth restriction (sIUGR), and liquor and/or growth discordance (L/GD) not meeting TTTS or sIUGR criteria. TTTS and sIUGR were case-control matched. Routine Dopplers and MPI were taken and correlated to diagnosis and final outcome. Results: Twenty-six always uncomplicated pairs, 51 always complicated pairs, and seven uncomplicated to pathological pairs were included. TTTS recipient (n = 25) left and right MPI and intertwin difference (ITD) were significantly elevated, however, were already elevated in Stage I (n = 10), and did not predict progression or pregnancy outcome. sIUGR MPI (n = 11) did not differ significantly from control. Of 15-L/GD pairs, two that progressed to TTTS had significantly higher left and right MPI values in the future recipient (0.61 and 0.72) versus future sIUGR larger twins (0.48 and 0.51) or stable L/GD (0.47 and 0.52): p < .01 for all comparisons. Conclusions: In this cohort, MPI did not add substantial diagnostic/prognostic information to current routine evaluation in established TTTS or sIUGR though potentially differentiated L/GD cases progressing to TTTS.

Applying spatial-temporal image correlation to the fetal kidney: Repeatability of 3D segmentation and volumetric impedance indices

Spatiotemporal image correlation (STIC) can evaluate fetal renal impedance using four‐dimensional volumetric indices. We assessed repeatability of three‐dimensional kidney segmentation and the repeatability of the resultant indices.

Beat‐to‐beat variability of fetal myocardial performance index

To determine whether there is beat‐to‐beat (BTB) variability in the fetal left myocardial performance index (MPI), as evaluated by an automated system, and whether there is a correlation between MPI and fetal heart rate (FHR).

Beat-to-beat variability of fetal myocardial performance index: Beat-to-beat variability of MPI

To determine whether there is beat‐to‐beat (BTB) variability in the fetal left myocardial performance index (MPI), as evaluated by an automated system, and whether there is a correlation between MPI and fetal heart rate (FHR).

P19.03: Evaluation of emerging modalities for fetal global cardiac function assessment in normal pregnancies

Objectives: To determine correlation between macroscopic appearances of superficial endometriotic lesions noted at laparoscopy and the final histopathology diagnosis. Methods: A prospective cohort study involving consecutive women with chronic pelvic pain who underwent laparoscopy between January 2015 December 2016. The laparoscopic findings were recorded in terms of location, number and morphological description (i.e. red spot, white spot, pocket and/or fibrous adhesion) of the endometriotic lesions. These findings were correlated with the final histopathological diagnosis. All endometriotic lesions were excised at the time of laparoscopy. Results: A total of 77 consecutive women underwent laparoscopy. 9/77 were noted to have deep infiltrating endometriosis with bowel involvement and were excluded. 4/77 had a negative laparoscopy with normal pelvis. 64/77 had visualised lesions suspicious of superficial endometriosis. The mean age of the women was 27.7±7.7 y, 37% were nulliparous, 27.5% had previous history of endometriosis. A total of 180 biopsies were collected .The description of lesion were: red spots74/180, white spot 87/180, peritoneal pocket 11/180 and adhesions 8/180. Overall histopathological confirmation rate for endometriosis was 56%.There was no correlation between lesion distribution, morphology and positive diagnosis of endometriosis (p-value=0.8). These parameters were not statistically different in the presence of past history of endometriosis (p-value=0.19). Conclusions: Although the numbers in this study are small, there is no correlation between the macroscopic appearance of superficial endometriosis lesions and gold standard histological confirmation.

OP02.06: Evaluation of multimodality, global fetal cardiac function assessment in pregnancies complicated with IUGR, TTTS and sIUGR

Objectives: In fetal life, aortic coarctation (AC) induces significant right ventricular dominance, but no other ventricular morphologic changes have been fully described. We aimed to describe the ventricular remodelling in fetuses with AC. Methods: A comprehensive echocardiography was performed at third trimester of pregnancy in 21 fetuses with confirmed AC (2011-2016). Two gestational-age (GA) matched controls were selected for each case. GA and estimated fetal weight (EFW) were recorded. Cardiac morphologic assessment included end-systolic (ES) and end-diastolic (ED) ventricular diameters and ventricular wall thickness. ES and ED sphericity indexes were calculated for both ventricles (longitudinal/basal and longitudinal/mid-transverse diameters). Results: GA and EFW at echocardiography were similar between groups (31.6 vs. 31.7 weeks and 1946 vs. 1951g, respectively). Fetuses with AC showed higher right/left ventricular ratios measured at basal (ED 1.51 vs. 1.03; ES 1.50 vs. 1.07; p<0.001) and mid-transverse (ED 1.72 vs. 1.1; ES 1.78 vs. 1.18; p<0.001) levels. Right sphericity indexes were similar in AC and controls but both ES and ED left sphericity indexes were significantly higher in fetuses with AC (ED-basal 2.26 vs. 1.80; ED-mid-transverse 2.34 vs. 1.82; ES-basal 1.99 vs. 1.75; ES-mid-transverse 2.44 vs. 1.98; p<0.01). Septal, right and left free wall thickness was similar between groups in ES and ED (p>0.15). Conclusions: Fetuses with severe AC present a significantly more elongated left ventricle. Despite significant right/left ventricular dominance, the right ventricular shape and myocardial thickness seem to be preserved.