Fetal intestinal loop dilatation: Follow-up and outcome of a series of 133 consecutive cases (the DILDIG study).

OBJECTIVES: To define the prognostic markers of fetal dilated bowel loops. METHODS: National non-interventional study of 133 consecutive prenatal observations of dilated loops including ultrasound examinations, complementary laboratory tests, magnetic resonance imaging (MRI), outcomes, and postnatal diagnosis. RESULTS: One hundred twenty seven cases were classified according to outcome: Group 1, very severe (n = 43), Group 2, children needing specific care (n = 39), and Group 3, healthy children (n = 45). Prenatal ultrasound scan suggested duodenal obstruction in 30 cases, small bowel obstruction in 81, colonic obstruction in 11, and diffuse dilatation in 5. Diameter of dilated loops did not significantly differ between the groups. A poor prognosis was significantly associated with duodenal obstruction, genetic anomalies (53% vs. 21.8%), including aneuploidies or CFTR gene mutations and abnormal amniotic fluid biochemistry (86.4% vs. 38.7%). A good prognosis was associated with regression of dilatation and normal MRI. CONCLUSION: In this study, postnatal outcomes for fetuses with intestinal dilatation were best predicted by assessing the level of obstruction with prenatal ultrasound and MRI, determining the presence of associated malformations, amniotic fluid biochemical and genetic testing, and monitoring for regression of bowel dilatation. These results should help inform future guidelines on the prenatal and neonatal management of congenital intestinal obstruction.

Impact of a shift in nuchal translucency measurements on the detection rate of first-trimester Down syndrome screening: A population-based study.

OBJECTIVE: To assess the distribution of nuchal translucency (NT) measurements following a national policy without credentialing and its impact on first-trimester Down syndrome screening (DSS) detection rate. METHOD: All first-trimester DSS data recorded in France (2010-2014) were collected by the laboratories in charge via an Internet database (https://www.bionuqual.org/echo.php). There was no minimal requirement for image quality to allow sonographers to enter the screening process. A subgroup of DSS with complete DS follow-up corresponded to 1614 sonographers. Based on the distribution of maternal age, DS detection rate was calculated and split as a function of the distribution of NT multiple of the median (MoM). RESULTS: Four thousand nine hundred forty-three sonographers performed 2,337,372 NT measurements. Median NT expressed in MoM was 0.83. Screenings with complete follow-up consisted of 197,417 screenings, in which DSS detection rates were respectively 70.4%, 70.9%, 79.4%, 87.7%, and 79.5% for the following median NT MoM ranges: <0.7, 0.70 to 0.79, 0.80 to 0.89, 0.90 to 0.99, and >0.99 (trend χ = 12.21; P = .0158). CONCLUSION: In France, following a policy of quality assessment without standardized credentialing, the distribution of NT measurements did not fit the expected distribution. Down syndrome detection rate was 10% lower in screenings by sonographers with a median NT < 0.80 MoM.

Effect of Cell-Free DNA Screening vs Direct Invasive Diagnosis on Miscarriage Rates in Women With Pregnancies at High Risk of Trisomy 21: A Randomized Clinical Trial.

Importance: Cell-free DNA (cfDNA) tests are increasingly being offered to women in the first trimester of pregnancies at a high risk of trisomy 21 to decrease the number of required invasive fetal karyotyping procedures and their associated miscarriages. The effect of this strategy has not been evaluated. Objective: To compare the rates of miscarriage following invasive procedures only in the case of positive cfDNA test results vs immediate invasive testing procedures (amniocentesis or chorionic villus sampling) in women with pregnancies at high risk of trisomy 21 as identified by first-trimester combined screening. Design, Setting, and Participants: Randomized clinical trial conducted from April 8, 2014, to April 7, 2016, in 57 centers in France among 2111 women with pregnancies with a risk of trisomy 21 between 1 in 5 and 1 in 250 following combined first-trimester screening. Interventions: Patients were randomized to receive either cfDNA testing followed by invasive testing procedures only when cfDNA tests results were positive (n = 1034) or to receive immediate invasive testing procedures (n = 1017). The cfDNA testing was performed using an in-house validated method based on next-generation sequencing. Main Outcomes and Measures: The primary outcome was number of miscarriages before 24 weeks' gestation. Secondary outcomes included cfDNA testing detection rate for trisomy 21. The primary outcome underwent 1-sided testing; secondary outcomes underwent 2-sided testing. Results: Among 2051 women who were randomized and analyzed (mean age, 36.3 [SD, 5.0] years), 1997 (97.4%) completed the trial. The miscarriage rate was not significantly different between groups at 8 (0.8%) vs 8 (0.8%), for a risk difference of -0.03% (1-sided 95% CI, -0.68% to ∞; P = .47). The cfDNA detection rate for trisomy 21 was 100% (95% CI, 87.2%-100%). Conclusions and Relevance: Among women with pregnancies at high risk of trisomy 21, offering cfDNA screening, followed by invasive testing if cfDNA test results were positive, compared with invasive testing procedures alone, did not result in a significant reduction in miscarriage before 24 weeks. The study may have been underpowered to detect clinically important differences in miscarriage rates. Trial Registration: ClinicalTrials.gov Identifier: NCT02127515.

The impact of insonation angle on four-chamber view image quality: an observational study on 2866 routine scans.

OBJECTIVE: To determine insonation angles achieved in routine screening practice and their impact on image quality. METHODS: Prospective cross-sectional observational survey of 2866 four-chamber views produced by 287 senor ultrasonographers, from unselected routine second-trimester screening scans. Images were scored from 0 to 5 according to whether two atria, two ventricles, the heart crux, the apex, and the descending aorta were seen. Images were considered adequate if two atria, two ventricles, and the heart crux were seen. The insonation angle was classified as apical, basal, or lateral according to the orientation of the fetal heart to the ultrasound beam. RESULTS: There were 1612 (56.3%) apical, 869 (30.3%) basal, and 385 (13.4%) lateral views. The mean score and the rate of adequate images were significantly greater in the apical group (4.56 and 81.8%) than in the basal group (4.19 and 71.1 %) and were significantly greater in the basal group than in the lateral one (3.6 and 30.9%), p < 0.001. Angle of insonation and image quality were not correlated with the experience of the operator. CONCLUSIONS: Adequate four-chamber view images are best obtained with an apical or basal insonation angle, which could be achieved in 8 out of 10 scans. © 2015 John Wiley & Sons, Ltd.

Quality of first-trimester measurement of crown-rump length.

OBJECTIVE: The purpose of this study was to evaluate the quality of crown-rump length (CRL) measurements in scans judged to be of high quality for the measurement of the nuchal translucency. STUDY DESIGN: We analyzed prospective data on 68,250 scans by 1913 sonographers that were collected by the French College of Fetal Echography (CFEF) national practice assessment program for the first-trimester scan. The scans were evaluated according to the CFEF image scoring method (CFEF-ISM), which includes items to measure the quality of the scan for both nuchal translucency and the CRL measurements. The scans were classified into 4 quality groups with the use of the full CFEF-ISM score and then a shortened version of the CFEF-ISM that excluded the item on quality of CRL measurement. The proportion of scans with an inaccurate CRL measurement was compared across the different quality groups. RESULTS: Overall, 21.67% of scans were of insufficient quality for CRL measurement. Among 23,764 "excellent" scans according to the full CFEF-ISM, 965 scans (4.06%) had insufficient CRL quality vs 9.24% of scans with "excellent" quality on the short CFEF-ISM (relative risk, 2.27; 95% confidence interval, 2.11-2.44; P < .001). CONCLUSION: High scores of the quality of nuchal translucency measurement do not guarantee accurate measurement of crown-rump length. Specific measures are needed to evaluate and to improve the quality of the measurement of crown-lump length.

Nuchal translucency measurement: are qualitative and quantitative quality control processes related?

OBJECTIVES: Two types of quality assurance processes for nuchal translucency (NT) measurement have been described: qualitative through review of images and quantitative comparison of operator's specific NT distribution to reference distributions. The aim of this study was to assess the results of these two approaches. METHODS: Prospective evaluation of sonologists affiliated to the French Ultrasound College who first underwent qualitative evaluation based on the College Français d'Echographie Foetale (CFEF) score. During one year, those same sonologists measured the NT for Down syndrome screening purposes. The operator's specific NT distributions were compared to their CFEF score, their number of unsatisfactory images and their number of NT measurements per year. RESULTS: The study involved 1726 sonologists who performed 174 722 first-trimester examinations. Mean (SD) quantitative score was 23.4/32 (+/-7.4). The median [inter-quantile range] number of examinations per sonologist was 69 [37; 123]. The median [range] NT multiples of the mean (MoM) value was 0.81 [0.46; 1.22]. NT (MoM) absolute deviation from 1 MoM was significantly correlated with mean score obtained (R(2) = -0.17, p < 0.0001), number of unacceptable images (R(2) = 0.14, p < 0.0001) and number of ultrasound scans performed per year (R(2) = -0.19, p < 0.0001). CONCLUSION: Our results suggest that both processes are clearly related.

Online audit and feedback improve fetal second-trimester four-chamber view images: a randomised controlled trial.

OBJECTIVES: We aimed to study the impact of online audit and feedback on fetal four-chamber view image quality. METHODS: Ultrasonographers uploaded a set of four-chamber views from 10 consecutive screening examinations and a second set 3 months later. They were randomised to receive (group A) or not (group B) a feedback for their first set. The primary outcome was the difference in image mean score and in percentage of inadequate images between the first set and the second set, comparing the groups with and without feedback. RESULTS: There were 258 ultrasonographers who completed the trial (group A: 122; group B: 136), and 5160 images were audited. In both groups, the mean score increased. In group A, it rose from 17.0 to 18.5 (p < 0.0001), and in group, B from 17.6 to 18.3 (p < 0.0001). The improvement was greater in group A than in group B (1.5 vs. 0.7, p = 0.0007). The mean percentage of inadequate images decreased in both groups. In group A, it dropped from 32% to 19% (p < 0.0001), and in group B, from 26% to 21% (p = 0.012). The decrease was greater in group A than in group B (13% vs. 5%, p = 0.007). CONCLUSIONS: Image quality improved following online audit, the improvement being slightly greater with feedback.

Formative assessment based on an audit and feedback improves nuchal translucency ultrasound image quality.

OBJECTIVES: The purpose of this work was to study the impact of an audit and feedback on the quality of routine first-trimester nuchal transparency ultrasound images. METHODS: Eighty-eight sonographers were each sent 2 different series of 30 consecutive nuchal translucency images at a mean interval of 3 months to a dedicated, protected server for remote double-blind independent analysis based on the new Collège Français d'Echographie Foetale/Centre National de la Recherche Scientifique image-scoring method (https://www.cfef.org/evaluation/ISMCFEFCNRS.pdf). The sonographers were classified as low (score below the median) or high (score above the median) scorers for each series. Before their second evaluation, 73 of the 88 sonographers received a feedback report on their first series of images, whereas the other 15 participants received no feedback. The baseline characteristics of the participants who did and did not receive feedback were comparable. RESULTS: Participants who received feedback increased their average score significantly, from a mean ± SD of 11.1 ± 1.3 to 13.4 ± 1.4 among low scorers (P < .00001) and from 15.1 ± 1.2 to 16.0 ± 1.4 among high scorers (P < .001), whereas no significant change was seen among participants who received no feedback (low scorers, 10.9 ± 1.5 to 12.1 ± 2.0; P = .11; high scorers, 14.7 ± 1.3 to 14.6 ± 1.3; P = .99). The proportion of satisfactory images increased by 48% among low scorers who received feedback. CONCLUSIONS: Formative assessment based on a moderately intensive audit and feedback is feasible and effective for improving the quality of routine first-trimester nuchal transparency ultrasound images.

Women's Attitudes Toward Invasive and Noninvasive Testing When Facing a High Risk of Fetal Down Syndrome.

Importance: Noninvasive prenatal testing (NIPT) using cell-free DNA in maternal blood is increasingly common compared with invasive testing (IT) in routine antenatal detection of Down syndrome (DS). Objective: To assess attitudes and decision making in pregnant women facing a risk of fetal DS greater than 1 in 250 as established by combined first trimester screening at 11 to 14 weeks of gestation. Design, Setting, and Participants: Survey study in which data were collected from pregnant women at high risk of fetal DS participating in a randomized clinical trial. Data were collected from April 8, 2014, to April 7, 2016, in 57 prenatal diagnosis centers in France. Data were analyzed in 2018. Interventions: Data on attitudes were collected prior to offering randomization between NIPT and IT, whereas data on decision making and test results were collected as part of the clinical trial. Main Outcome and Measures: The primary outcome related to attitudes. A hierarchical cluster analysis was conducted to identify clusters with contrasting attitudes. Logistic regression analyses were used to identify factors associated with attitudes. Results: All 2436 consecutive women to whom the study was proposed (mean [SD] age, 36.3 [5.0] years) answered the questionnaire: 515 (21.1%) expressed preference toward IT with complete karyotyping, whereas 1843 (75.7%) favored NIPT with almost certain but limited information. Hierarchical cluster analysis yielded 4 different clusters that mainly differed in attitudes toward risk taking and extent of information seeking. Factors likely associated with attitudes driven by risk aversion were mostly age and religious beliefs (adjusted odds ratio [aOR], 1.03; 95% CI, 1.00-1.05; P = .03 and aOR, 1.62; 95% CI, 1.29-2.04; P < .001, respectively), whereas higher nuchal translucency measurements by ultrasonography were associated with attitudes driven by ambiguity aversion (aOR, 1.67; 95% CI, 1.27-2.20; P < .001). For attitudes involving both risk and ambiguity aversion at different extents, lower education was associated with highly valuing all possibilities of getting information on pregnancy, whereas higher education was associated with highly valuing information on fetal DS as a primary concern (aOR, 0.54; 95% CI, 0.44-0.67; P < .001 and aOR, 1.44; 95% CI, 1.20-1.74; P < .001, respectively). In all, decision making was in line with attitudes. Conclusions and Relevance: Aversion to risk of fetal loss related to IT and aversion to ambiguity generated by incomplete information from NIPT played a major role in shaping attitudes and decision making. Informed decision making should require pregnant women at high risk of DS to receive extensive information on targeted abnormalities by both tests.

Association between amniotic fluid evaluation and fetal biometry: a prospective French "Flash" study.

We aimed to study the association between three different methods of assessing the amount of amniotic fluid (subjective method (SM), deepest vertical pocket (DVP) and amniotic fluid index (AFI)) and estimated fetal weight (EFW) (in percentile or Z-score) after adjustment on maternal-fetal parameters. We performed a nationwide cross-sectional study through the French network of obstetric sonographers using the "flash" study method and including low-risk singleton pregnancies from 18-40 weeks. Crude and adjusted odds ratio were computed after stratification upon 2nd and 3rd trimester of pregnancy. 1667 ultrasound scans performed by 65 operators were included. Only Z-score of EFW was significantly associated with SM in both trimesters. For DVP and AFI, Z-score of EFW and male fetal gender was significantly associated with them in 2nd trimester. In the 3rd trimester, both Z-score of EFW and large (LGA) or small for gestational age (SGA) fetus were significantly associated with AFI. and DVP. Overweight woman and class I obesity women were also significantly associated with DVP modification. In conclusion, all three methods of amniotic fluid evaluation are significantly associated to estimated fetal weight. DVP and AFI appeared equivalent except that maternal-fetal factors seemed to have a higher impact in DVP than AFI.

Quality control of an image-scoring method for nuchal translucency ultrasonography.

OBJECTIVE: The objective of the study was to describe a new image-scoring method (NISM) for the measurement of nuchal translucency and crown-rump length on ultrasound scans and to establish interreviewer reliability. STUDY DESIGN: This NISM was based on 8 criteria on a scale of 4 levels (1-4) established on clearly defined ultrasound reference marks. Ten reviewers assessed the same images of 30 fetuses. After a short training period, the same images and those of 30 new fetuses were scored by these 10 reviewers. RESULTS: The differences in scores among the 10 reviewers were significant for 4 of 45 pairwise comparisons before training, but no pairwise comparison was significant after training. Interreviewer variance was significantly lower after training (P = .045). The intraclass correlations before and after training were 0.75 and 0.82. For each criterion, the scores were dichotomized into 2 categories (1-2 vs 3-4). Kappa values for each criterion were substantial (0.61 to 0.80) or even almost perfect (0.81 to 1.00). CONCLUSION: This NISM was highly reliable for the total scores and for each criterion evaluating the image of nuchal translucency and crown-rump length and provides a relevant quality control tool for ultrasound operators.

A standardized approach for the assessment of the lower uterine segment at first trimester by transvaginal ultrasound: a flash study.

OBJECTIVES: To evaluate the reproducibility of a standardized approach to lower uterine segment (LUS) imaging by transvaginal ultrasound at 11-14 weeks. METHODS: This was a "flash" study lasting for 1 month. Obstetrician-sonographers performing more than 50 first trimester ultrasounds per year participated. All consecutive women attending for their 11-14 weeks scan were included. A standardized, transvaginal approach to the imaging of LUS was defined. The sonographers recorded one or two images of the LUS. The quality of the images was assessed by sonographers and reviewed by an independent fetal medicine specialist using the same scoring system. Inter and intra-reviewer variability was assessed. RESULTS: Seventy-one sonographers and 851 pregnant women participated. The mean (±SD) and medium (IQR) scores attributed by sonographer versus reviewer were 5.01 (±0.92) and 5 [4-6] versus 4.68 (±1.14) and 5 [4-5.24], p = 0.08. The mean [95% CI] difference of -0.33 [-2.6;2] was recorded. There was good, moderate and poor agreement in 74.4%, 16.7% and 8.9% cases, respectively. Variability in inter-reviewer and intra-reviewer was low with the mean [95% CI] difference of -0.1 [-1.6;1.4] and -0.1 [-1.4;1.2] respectively. CONCLUSIONS: A standardized approach to LUS imaging at 11-14 weeks is feasible and highly reproducible in a large population.

Gas bubbles in simulation and experiment.

An experimental setup for the examination of single bubbles, rising in a liquid, is presented. Its main part is a rotating chamber, in which the bubble is spatially stabilized by a balance of buoyancy, drag, and lift forces. This allows for long observation periods in time. Experimental results are presented for air bubbles in silicone oil. The experimental results are validated by a comparison with numerical simulations. A modified, mass-conserving level-set method is used for the representation of the free interface, while an immersed-boundary formulation is engaged for the conservation equations. The agreement between experiment and simulation, and to available correlations from literature, is found to be perfect. It is shown that the influence of the liquid shear due to the rotation is negligible. Also, for the presented liquid system, no influence by Marangoni stresses could be found, which makes the system of air and silicone oil a good choice for validation purposes.