Ductus Venosus Pulsatility Index For Veins Research Articles

First trimester screening for major cardiac defects based on the ductus venosus flow in fetuses with trisomy 21.

To examine whether in fetuses with trisomy 21 (T21), the ductus venosus (DV) flow differs in presence of a major cardiac defect (congenital cardiac defect [CHD]) and whether this affects the risk distribution in first trimester screening for T21. This retrospective study included pregnant women who underwent first trimester screening. This involves an examination of the crown-rump length, the nuchal translucency, the ductus venosus (DV) flow, and the heart. Three groups of fetuses were examined: euploid without CHD, T21 with CHD, and T21 without CHD. We examined the DV pulsatility index for veins, the direction of the a-wave, and ratios of velocities: v/S, v/D, a/S, a/D, and S/D. The study population consisted of 410 euploid fetuses and 136 with T21 (51 with CHD and 85 without CHD). In the 3 groups, the a-wave was reversed in 3.2%, 66.7%, and 57.6%. The DV flow ratios in T21 with and without CDH were significantly different compared with normal fetuses. When comparing the ratios between the 2T21 groups, only the a/S and a/D ratio were significantly different. The risk distributions in screening for T21 with and without CDH were similar. There are some small differences in the DV flow of T21 fetuses with and without CHD, but they are not clinically useful.

First-trimester ultrasound screening for trisomy 21 based on maternal age, fetal nuchal translucency, and different methods of ductus venosus assessment.

To examine whether combining the dichotomous assessment of the a-wave and the ductus venosus (DV) pulsatility index for veins (PIV) measurement improves first-trimester screening performance. Retrospective study performed at the University Hospital of Tuebingen based on singleton pregnancies that underwent first-trimester screening including DV flow assessment. In each case, the risk of trisomy 21 was calculated based on maternal age, fetal nuchal translucency, and DV flow either as dichotomous classification of the a-wave, as measurement of the DV PIV, or both. There were 5280 euploid fetuses and 127 fetuses with trisomy 21. The DV a-wave was reversed in 2.3% and 66.1% in the euploid and trisomy 21 cases, respectively. The DV PIV measurements were above the 95th percentile in 8.3% and 77.2% the euploid and trisomy 21 cases, respectively. For a false positive rate of 3%, the detection rate for trisomy 21 based on maternal age, fetal NT, and DV flow is about 87% irrespective of whether DV is examined as a continuous or dichotomous variable. The combination of both resulted in a small decrease at 3% false positive rate. Assessment of the DV a-wave and the DV PIV result in similar DRs. Combining these two approaches does not appear to improve their individual screening performance. © 2017 John Wiley & Sons, Ltd.

Prediction of stillbirth from placental growth factor at 11-13 weeks.

To investigate whether the addition of maternal serum placental growth factor (PlGF) measured at 11-13 weeks' gestation improves the performance of screening for stillbirths that is achieved by a combination of maternal factors and first-trimester biomarkers such as maternal serum pregnancy-associated plasma protein-A (PAPP-A), fetal ductus venosus pulsatility index for veins (DV-PIV) and uterine artery pulsatility index (UtA-PI) and to evaluate the performance of screening with this model for all stillbirths and those due to impaired placentation and unexplained causes. This was a prospective screening study of 45 452 singleton pregnancies including 45 225 live births and 227 (0.49%) antepartum stillbirths; 131 (58%) were secondary to impaired placentation and 96 (42%) were due to other or unexplained causes. Multivariable logistic regression analysis was used to determine whether the addition of maternal serum PlGF improved the performance of screening that was achieved by a combination of maternal factors and PAPP-A, DV-PIV and UtA-PI. Significant contribution to the prediction of stillbirth was provided by maternal factor-derived a-priori risk and multiples of the median values of PlGF, DV-PIV and UtA-PI but not of serum PAPP-A. A model combining these variables predicted 42% of all stillbirths and 61% of those due to impaired placentation, at a false-positive rate of 10%; within the impaired placentation group the detection rate of stillbirth < 32 weeks' gestation was higher than that of stillbirth ≥ 37 weeks (71% vs 46%; P = 0.031). A high proportion of stillbirths due to impaired placentation can be identified effectively in the first trimester of pregnancy. Addition of PlGF improves the performance of screening achieved by other maternal factors and biomarkers. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Prediction of stillbirth from biochemical and biophysical markers at 11-13 weeks.

To develop a model for the prediction of stillbirth that is based on a combination of maternal characteristics and medical history with first-trimester biochemical and biophysical markers and to evaluate the performance of screening with this model for all stillbirths and those due to impaired placentation and unexplained causes. This was a prospective screening study of 76 897 singleton pregnancies, including 76 629 live births and 268 (0.35%) antepartum stillbirths; 157 (59%) were secondary to impaired placentation and 111 (41%) were due to other or unexplained causes. Multivariable logistic regression analysis was used to determine if there was a significant contribution to prediction of stillbirth from the maternal factor-derived a-priori risk, fetal nuchal translucency thickness, ductus venosus pulsatility index for veins (DV-PIV), uterine artery pulsatility index (UtA-PI) and maternal serum free β-human chorionic gonadotropin and pregnancy-associated plasma protein-A (PAPP-A). The significant contributors were used to derive a model for first-trimester prediction of stillbirth. Significant contribution to prediction of stillbirth was provided by maternal factors, PAPP-A, UtA-PI and DV-PIV. A model combining these variables predicted 40% of all stillbirths and 55% of those due to impaired placentation, at a false-positive rate of 10%. Within the impaired-placentation group, the detection rate of stillbirth < 32 weeks' gestation was higher than that of stillbirth ≥ 37 weeks (64% vs 42%). A model based on maternal factors and first-trimester biomarkers can potentially predict more than half of subsequent stillbirths that occur due to impaired placentation. The extent to which such stillbirths could be prevented remains to be determined. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Doppler assessment of the ductus venosus and the tricuspid valve at 11-13+6weeks: Reference ranges and development of sonographic quality assurance standards.

To develop reference ranges for the ductus venosus (DV) and tricuspid valve (TV) waveforms at 11-14weeks and define auditable standards to assess operator measurement performance. A single operator prospectively obtained quantitative measurements of a number of DV and TV Doppler indices to develop medians and 90% reference intervals (RIs). Measurement agreement studies between two experienced operators were also performed. The measurement bias of three additional operators was subsequently assessed using the newly defined auditable standards. Doppler measurements were obtained in 292 patients (DV) and 321 patients (TV). Reference ranges were constructed for DV pulsatility index for veins (PIV) which did not change over gestation (mean 1.06; 90% RI 0.86-1.23) and for the TV E-A ratio reference range which was positively correlated with gestation. Measurement agreement studies on 30 additional patients showed the within-operator agreement was almost perfect for DV PIV (ICC, intraclass correlation 0.82-0.86) and strong for TV E-A ratio (ICC 0.68-0.78) while the between-operator agreement was good for both DV PIV and TV E-A ratio measurements (ICC 0.46 for both). Development of local reference ranges enabled the definition of quantitative auditable standards that can be utilised in assessment of operator training and ongoing Doppler measurement quality assurance. Measurements of DV PIV and TV E-A ratio by experienced operators were found to be reproducible.

First-trimester contingent screening for trisomies 21, 18 and 13 by fetal nuchal translucency and ductus venosus flow and maternal blood cell-free DNA testing

Objective To examine performance of screening for major trisomies by a policy of first-line assessment of risk according to maternal age, fetal nuchal translucency thickness (NT) and ductus venosus pulsatility index for veins (DV-PIV) followed by cell-free DNA (cfDNA) testing in pregnancies with an intermediate risk. Methods We estimated the distribution of risks based on maternal age, fetal NT and DV-PIV in a dataset of 86 917 unaffected and 491 trisomic pregnancies undergoing prospective screening for trisomies. Performance of screening for trisomies by cfDNA testing was derived from a meta-analysis of clinical validation studies. We estimated performance and cost of screening for trisomies using different combinations of ultrasound screening and cfDNA testing.

First-trimester contingent screening for trisomies 21, 18 and 13 by fetal nuchal translucency and ductus venosus flow and maternal blood cell-free DNA testing.

To examine performance of screening for major trisomies by a policy of first-line assessment of risk according to maternal age, fetal nuchal translucency thickness (NT) and ductus venosus pulsatility index for veins (DV-PIV) followed by cell-free DNA (cfDNA) testing in pregnancies with an intermediate risk. We estimated the distribution of risks based on maternal age, fetal NT and DV-PIV in a dataset of 86 917 unaffected and 491 trisomic pregnancies undergoing prospective screening for trisomies. Performance of screening for trisomies by cfDNA testing was derived from a meta-analysis of clinical validation studies. We estimated performance and cost of screening for trisomies using different combinations of ultrasound screening and cfDNA testing. Screening for trisomies 21, 18 and 13 according to a combination of maternal age, fetal NT and DV-PIV in all pregnancies, followed by invasive testing in the high-risk group (≥ 1:10) and cfDNA testing in the intermediate-risk group (1:11-1:3000) can potentially detect about 96%, 95% and 91% of cases, respectively, with a false-positive rate (FPR) of 0.8%. On the assumption that the costs for ultrasound screening, cfDNA testing and invasive testing are €150, €500 and €1000, respectively, the overall cost of such a policy would be about €250 per patient. The alternative policy, of universal screening by cfDNA testing, can potentially detect about 99%, 97% and 92% of cases of trisomies 21, 18 and 13, but at an overall cost of more than €500 per patient. Incorporation of cfDNA testing into a contingent policy of early screening for the major trisomies, based on the risk derived from first-line screening by a combination of maternal age, fetal NT and DV-PIV, can detect a high proportion of affected cases with a low FPR.

Reference Ranges for Ductus Venosus Velocity Ratios in Pregnancies With Normal Outcomes

The purpose of this study was to establish reference ranges for ductus venosus velocity ratios. Singleton pregnancies from 11 to 38 weeks with exactly established gestational ages (GAs) were recruited for the study. Pregnancies with fetal anomalies, growth abnormalities, maternal medical complications, stillbirth, birth weight below the 10th or above the 90th percentile, and neonatal anomalies were excluded. The ductus venosus pulsatility index for veins (PIV) and velocity ratios (S/v, S/D, v/D, S/a, v/a, and D/a, where S indicates ventricular systole [s-wave], v, ventricular end-systolic relaxation [v-descent], D, passive diastolic ventricular filling [D-wave], and a, active ventricular filling during atrial systole [a-wave]) were calculated. Separate regression models were fitted to estimate the mean and standard deviation at each GA for each ratio. A total of 902 velocity wave ratios and ductus venosus PIVs were used for reference ranges. The S/v, S/D, and v/D ratios were not changed with GA (P > .05 for all). The PIV and S/a, v/a, and D/a ratios were reduced with GA (P < .0001 for all). Significant reductions in the means and standard deviations of the PIV and S/a, v/a, and D/a ratios were observed between 17 and 18 weeks' gestation. Therefore, nomograms were separately created between 11 and 17 weeks and 18 and 38 weeks. We created reference ranges for ductus venosus velocity ratios between 11 and 38 weeks' gestation in normal pregnancies. These reference ranges may prove beneficial for evaluation of fetal conditions that are associated with cardiovascular abnormalities.

Cord blood B-type natriuretic peptide levels in placental insufficiency: correlation with fetal Doppler and pH at birth

ObjectiveTo examine the correlation of cardiac B-type natriuretic peptide (BNP) concentrations in umbilical cord blood at birth with fetal Doppler parameters and pH at birth. Study designProspective cross-sectional study with the following inclusion criteria: women with a singleton pregnancy, placental insufficiency characterized by increased pulsatility index (PI) of the umbilical artery (UA), intact membranes, and absence of fetal abnormalities. The exclusion criteria kept out cases of newborns with postnatal diagnosis of abnormality and cases in which the blood analysis was not performed. The Doppler parameters used were the UA PI, middle cerebral artery (MCA) PI, cerebroplacental ratio (CPR), and ductus venosus (DV) PI for veins (PIV), all converted into zeta scores. Blood samples were obtained from the umbilical cord immediately after delivery to measure the pH of the UA and the BNP. ResultsThirty-two pregnancies with placental insufficiency were included, 21 (65%) with positive diastolic flow and 11 (35%) with absent or reversed end diastolic flow in the UA. The concentration of BNP correlated significantly with the UA PI z-score (rho=0.43, P=0.016), the CPR z-score (rho=−0.35, P=0.048), the DV PIV z-score (rho=0.61, P<0.001), pH at birth (rho=−0.39, P=0.031), and gestational age (rho=−0.51, P=0.003). In the multiple regression analysis, antenatal parameters were included; the DV PIV z-score (P=0.008) was found to be an independent parameter correlating with BNP at birth. Correlation between BNP and the DV PIV z-score was borne out by the regression equation Log[BNP]=2.34+0.13*DV (F=18.8, P<0.001). Correlation between BNP and pH at birth was confirmed by the regression equation Log[BNP]=21.36–2.62*pH (F=7.69, P=0.01). ConclusionThe results suggest that fetal cardiac dysfunction identified by BNP concentrations at birth correlated independently with changes in DV PIV and correlated negatively with pH values at birth.

Abnormal ductus venosus pulsatility index in the absence of concurrent umbilical vein pulsations does not indicate worsening fetal condition

Recordings of blood flow velocity waveforms in the ductus venosus (DV) and umbilical vein (UV) are routinely used in order to predict fetal condition in high-risk pregnancies. The aim of this study was to investigate the relationship between pathological blood flow in the two vessels and perinatal outcome. High-risk pregnancies (n = 11 863) admitted from 1993 to 2011 for blood-flow examination, including recordings of DV pulsatility index for veins (DV-PIV) and UV pulsations, were included. The results were related to perinatal outcome, using the last Doppler examination prior to delivery in the analysis. Abnormal DV-PIV was observed in 3.9% of cases, intra-abdominal UV pulsations in 1.3% and pulsations in the cord in 0.7%. As expected, the rate of UV pulsations increased with increasing DV-PIV Z-score. Fetuses with a pathological DV-PIV, but without UV pulsations, showed fewer signs of compromise. This was also true for cases with a DV-PIV ≥ 4 SDs above the mean (53.7% had steady flow in the UV). In contrast, the occurrence of UV pulsations seemed to be an indicator of fetal compromise, regardless of level of DV-PIV. Abnormal fetal venous blood velocity is related to adverse outcome in high-risk pregnancies. However, abnormal DV-PIV is not a reliable indicator of fetal compromise unless UV pulsations are concurrently present, and should not be regarded an indication for emergency delivery.

First‐trimester detection of major cardiac defects with the use of ductus venosus blood flow

To assess the best method of combining fetal nuchal translucency (NT) and ductus venosus (DV) blood flow measurements in the detection of major cardiac defects in chromosomally normal fetuses during the first-trimester scan. During an 8-year period NT and DV blood flow were routinely assessed at 11-14 weeks' gestation. Only chromosomally normal singleton pregnancies were included in the study. When a cardiac defect was suspected, or when increased fetal NT and/or absent or reversed (AR) A-wave in the DV was observed, early fetal echocardiography was offered. Data on routine second- and third-trimester scans, neonatal follow-up or postmortem examination were obtained from hospital records. The detection and false-positive rates for all major cardiac defects were calculated for several screening strategies, including: NT or DV pulsatility index for veins (DV-PIV) above a fixed normal centile; AR A-wave; risk based on NT and DV-PIV or A-wave velocity above a fixed normal centile; and combinations of these strategies. The study population included 37 chromosomally normal fetuses with a major cardiac defect and 12 799 unaffected pregnancies. Fetal NT above the 95(th) or the 99(th) centile and AR A-wave was observed in 40, 27 and 39% of the fetuses with major cardiac defects, respectively. A 47% detection rate with a 2.7% false-positive rate was obtained when AR A-wave or NT above the 99(th) centile was used as the selection criterion. Half of major fetal cardiac defects could be detected in the first trimester if NT and DV Doppler are used to select 2.7% of the general pregnant population for extended fetal echocardiography.

Influence of fetal acidemia on fetal heart rate analyzed by computerized cardiotocography in pregnancies with placental insufficiency

Objective: To determine the influence of fetal acidemia on fetal heart rate (FHR) parameters analyzed by computerized cardiotocography (cCTG) in pregnancies with placental insufficiency.Methods: This was a cross-sectional study of 46 pregnancies with placental insufficiency between 26 and 34 weeks gestation by abnormal umbilical artery Doppler [pulsatility index (PI) > 95th percentile].Results: Twenty fetuses had acidemia at birth, pH < 7.20 (43.5%) and 26 had normal pH (56.5%). In the analysis of FHR parameters, fetal movements (FM) per hour was significantly lower in the group with acidemia (median = 2) when compared with the group with normal pH (median = 15, p = 0.019). The values of pH correlated positively with FM (ρ = 0.35; p = 0.019, 95% CI: 0.061 to 0.577) and basal FHR (ρ = 0.37, p = 0,011, 95% CI: 0.090 to 0.597) and negatively with the ductus venosus (DV) PI for veins (PIV) z-score (ρ = −0.31, p = 0,036, 95% CI: −0.550 to −0.021). Logistic regression showed that the DV PIV z-score (p = 0.0232) and basal FHR (p = 0.0401) were independent variables associated with acidemia at birth.Conclusions: The present results suggest that cCTG parameters may be useful in the management of cases with early onset placental insufficiency in association with Doppler velocimetry assessment, and that basal FHR and DV-PIV are most clearly in association with acidemia at birth.

First‐trimester contingent screening for trisomy 21 by biomarkers and maternal blood cell‐free DNA testing

To define risk cut-offs with corresponding detection rates (DR) and false-positive rates (FPR) in screening for trisomy 21 using maternal age and combinations of first-trimester biomarkers in order to determine which women should undergo contingent maternal blood cell-free (cf) DNA testing. From singleton pregnancies undergoing screening for aneuploidies at three UK hospitals between March 2006 and May 2012, we analyzed prospectively collected data on the following biomarkers: fetal nuchal translucency thickness (NT) and ductus venosus pulsatility index for veins (DV-PIV) at 11 + 0 to 13 + 6 weeks' gestation and serum free β-human chorionic gonadotropin (β-hCG), pregnancy-associated plasma protein-A (PAPP-A), placental growth factor (PlGF) and alpha-fetoprotein (AFP) at 8 + 0 to 13 + 6 weeks. Estimates of risk cut-offs, DRs and FPRs were derived for combinations of biomarkers and these were used to define the best strategy for contingent cfDNA testing. In contingent screening, detection of 98% of fetuses with trisomy 21 at an overall invasive testing rate < 0.5% can be potentially achieved by offering cfDNA testing to about 36%, 21% and 11% of cases identified by first-line screening using the combined test alone, using the combined test with the addition of serum PlGF and AFP and using the combined test with the addition of PlGF, AFP and DV-PIV, respectively. Effective first-trimester screening for trisomy 21, with DR of 98% and invasive testing rate < 0.5%, can be potentially achieved by contingent screening incorporating biomarkers and cfDNA testing.

Cardiovascular Transition to Extrauterine Life in Growth-Restricted Neonates: Relationship with Prenatal Doppler Findings

Objective: Cardiovascular status in fetal growth restriction (FGR) can be classified by the severity of individual Doppler abnormalities (early and late) or by the rate of clinical progression. We tested the hypothesis that aspects of the fetal cardiovascular status in FGR affect neonatal cardiovascular findings. Study Design: FGR cases [abdominal circumference <5th percentile and an elevated umbilical (MCA) artery (UA) pulsatility index] had UA, middle cerebral artery and ductus venosus (DV) Doppler. Positive UA end-diastolic velocity and/or a low MCA pulsatility index denoted early and absent/reversed UA end-diastolic velocity, whereas an increased DV pulsatility index for veins denoted late responses. The rate of progression was classified into mild, progressive and severe. After delivery, shunt dynamics and blood flow across the patent ductus arteriosus (PDA), foramen ovale and atriaventricular valves, myocardial contractility and pharmacologic pressor requirement were noted at neonatal echocardiography. These findings were related to prenatal Doppler parameters. Results: In 94 patients, only individual Doppler parameters related to neonatal echocardiographic findings. Absent/reversed UA DV significantly predicted PDA with right to left shunt (p = 0.016). The pressor need for cardiovascular instability was observed in neonates with abnormal prenatal DV Doppler and with lower birth weights delivered at earlier gestational age (p < 0.0001 for both). Pressor need was significantly related to neonatal death (Nagelkerke R² = 0.35, p = 0.002). Conclusion: A markedly abnormal UA Doppler predisposes growth-restricted neonates to persistence of fetal circulation associated with right to left shunting. Abnormal venous Doppler is a risk factor for cardiovascular instability which in turn significantly contributes to neonatal mortality. Further clarification of the neonatal cardiovascular transition may be helpful in guiding early neonatal assessment and management.

Agenesis of the ductus venosus: three-dimensional power Doppler reconstruction

The ductus venosus (DV) is an important fetal vascular structure that connects the umbilical venous system to the inferior vena cava (IVC) near its insertion point into the right atrium1. It allows 20–30% of the umbilical blood to bypass the liver in utero and reach the heart rapidly, thus increasing the flow of well-oxygenated blood to the cephalic and coronary circulation. The DV therefore plays a key role in increasing the shunt of oxygenated blood to the heart and decreasing placental return during hypoxemia and hypovolemia1,2. For several years, improvements in ultrasound techniques, such as two-dimensional (2D) and threedimensional (3D) ultrasound reconstruction, have made it possible to identify numerous malformations that were previously undetectable antenatally, including agenesis of the DV3, which is associated with various morphological and cytogenetic abnormalities. Examination of the DV has been used in referral centers to refine diagnoses involving cardiac, extracardiac and chromosomal anomalies2 as well as in first-trimester screening for Down syndrome in the high-risk population4. The DV pulsatility index for veins can be used as a continuous variable, in combination with nuchal translucency (NT) measurement, to increase specificity in the identification of congenital heart defects5. We report here the case of a 31-year-old primigravida, referred at 35 weeks of gestation to our prenatal center after the abnormal finding at third-trimester ultrasound of a highly dilated IVC (4.1 mm) and umbilical vein. Firstand second-trimester findings had been unremarkable. Combined marker screening in the first trimester indicated a 1/554 risk for Down syndrome, with NT on the 60th percentile. The only morphological abnormalities found during the third-trimester examination were the dilated IVC and umbilical vein. Suspecting agenesis of the DV, we performed a color Doppler ultrasound examination. Looking for an abnormal course or flow in the umbilical vein, we found that it was connected directly to the IVC and the flow velocity was high. To clarify the situation, 3D volume datasets were acquired with transverse and sagittal sweeps over the abdominal region. The umbilical vein and IVC were reconstructed using the glass-body rendering (angiographic) mode to optimize examination of these vessels. To highlight their abnormal connection, we then used the Magicut postprocessing application (Figure 1). This 3D power Doppler reconstruction demonstrated the anomalous course of the dilated umbilical vein, which was connected directly to the dilated subdiaphragmatic IVC and bypassed the liver. Fetal echocardiography showed substantial disproportion in the diameters of the IVC and superior vena cava at the points of insertion into the heart: 4.1 mm vs 1.2 mm. No features of cardiac decompensation or morphological abnormality were seen. The patient was offered amniocentesis for karyotype determination because agenesis of the DV is associated with a high rate (17%) of chromosomal abnormalities2; the karyotype was normal. The remainder of the pregnancy and delivery were uneventful, and the child appeared healthy. Little is known about the consequences and clinical implications of agenesis of the DV6. This anomaly affects approximately 6/1000 fetuses in a high-risk population. The few reports in the literature of an absent DV are associated with three different abnormal patterns: the umbilical vein may bypass the liver and then connect to the subdiaphragmatic IVC or to the iliac or renal veins, it may connect directly to the right or left atrium, or it may connect directly to the portal vein without giving rise to the DV2,7. DV agenesis is associated with congenital morphological abnormalities in approximately 65% of cases and with cytogenetic abnormalities in 17%2,8. The cardiac anomalies associated with DV agenesis, which occur in 48% of cases, include atrial and ventricular septal defects, tricuspid atresia, double outlet right ventricle, pulmonary atresia and transposition of the great arteries7,9. Other common associated anomalies involve the gastrointestinal system (duodenal atresia and tracheoesophageal fistula), the genitourinary system (bilateral hydronephrosis and ectopic kidney) and the musculoskeletal system

Is fetal cardiac function gender dependent?

An increased nuchal translucency (NT) is more common in males. A delayed diastolic cardiac function maturation has been proposed to explain this and the reported gender-related differences in ductus venosus (DV) flow. To investigate gender-related differences in fetal cardiac function. One hundred and ninety karyotypically/phenotypically normal fetuses with structurally normal hearts and known NT measurement, (104 > 95th percentile), were prospectively included between 1 October 2003 and 1 April 2009. They had been referred for fetal echocardiography. Three hundred and nine echocardiograms were performed between 11 and 35 weeks' gestation. The atrioventricular valve E- and A-wave peak velocity, E/A-velocity ratio and E/TVI ratio, myocardial performance index, semilunar valves acceleration time (AT) and peak velocity, stroke volume and cardiac output as well as DV pulsatility index for veins at 11-14 weeks' gestation, were measured. A multilevel analysis was performed using the NT (multiples of the median) as a continuous variable. The male : female ratio was 1.56:1. The tricuspid valve E/TVI was significantly higher and pulmonary valve AT significantly lower in females compared to males. No other significant differences in cardiac function were found. Our findings suggest better right ventricular (RV) relaxation and increased RV afterload in female fetuses, independent of NT thickness, between 11 and 35 weeks' gestation.

Cardiac function in trisomy 21 fetuses

Trisomy 21 is associated with an increased nuchal translucency thickness (NT), abnormal ductus venosus (DV) flow at 11-14 weeks' gestation and congenital heart defects (CHD), and cardiac dysfunction has been hypothesized as the link between them. We therefore aimed to investigate whether cardiac function is altered in trisomy 21 fetuses. Between December 2003 and June 2009, we performed echocardiography on 46 trisomy 21 fetuses (28 with structurally normal heart and 18 with CHD) and on 191 chromosomally/phenotypically normal fetuses with a confirmed normal heart (87 with normal NT and 104 with NT ≥ 95(th) percentile), between 11 and 35 weeks' gestation. Measurements included: E- and A-wave peak velocity, E/A velocity ratio and E/time velocity integral (TVI) ratio over atrioventricular valves; myocardial performance index (MPI); semilunar valve peak velocity and acceleration time; stroke volume (SV); cardiac output; and DV pulsatility index for veins (PIV) at 11-14 weeks' gestation. Data were categorized into three different age groups for analysis (11 to 13 + 6, 14 to 21 + 6 and 22 to 35 weeks' gestation). The tricuspid valve (TV) A-wave velocity and aortic valve peak velocity were significantly reduced in trisomy 21 compared with normal fetuses. Other highly significant differences found in trisomy 21 fetuses at 11-14 weeks' were increased TV-E/A ratio and DV-PIV, and decreased pulmonary valve peak velocity. We also observed evidence of left ventricular (LV) systolic dysfunction, reduced SV and increased MPI. After 14 weeks' gestation, the mitral valve A-wave peak velocity and E/TVI ratio were significantly reduced in the trisomy 21 fetuses with normal hearts compared with the controls with increased NT. In comparison with controls with normal or increased NT, cardiac function in trisomy 21 fetuses is abnormal irrespective of the presence of CHD. Evidence for cardiac loading (increased preload and afterload) and LV systolic (in the first trimester) and later diastolic dysfunction was observed.

First‐trimester measurement of the ductus venosus pulsatility index and the prediction of congenital heart defects

This study was carried out to evaluate the additional predictive value of ductus venosus pulsatility index for veins (DV-PIV) in the identification of congenital heart defects (CHDs) in fetuses with an enlarged nuchal translucency (NT) and a normal karyotype. All chromosomally normal fetuses referred to our Fetal Medicine Unit between September 1996 and December 2008 with known NT, DV-PIV and ductus venosus (DV) a-wave measurements were included. Intrafetus variation in DV-PIV was overcome by averaging three recordings. Follow-up included special focus on CHD. The odds of CHD at any NT and DV-PIV value were evaluated using logistic regression analysis. Of 792 fetuses included, the NT was enlarged (equal to or above the 95(th) percentile (P95)) in 318 (40.2%). The DV-PIV was abnormal (≥ P95) in 41.8% of the fetuses with an enlarged NT and the a-wave was abnormal (negative or reversed) in 29.9%. CHD was diagnosed in 35 fetuses, 33 of which had an enlarged NT. Amongst the fetuses with an enlarged NT, the sensitivities for CHD of abnormal DV-PIV and DV a-wave were 73% and 55%, with specificities of 62% and 73%, respectively. Logistic regression analysis showed that in this risk group the DV-PIV multiple of the median (MoM) (as a continuous variable) was significantly associated with the risk of CHD (odds ratio = 2.4), independent of the degree of NT enlargement, whereas the DV a-wave did not significantly add to the prediction of CHD. Two-thirds of fetuses with an enlarged NT, a normal karyotype and CHD have an increased DV-PIV. DV-PIV can be used as continuous variable in combination with NT to increase specificity in the identification of CHD and to refine the individual risk assessment.

Cerebroplacental ratio and acidemia to the birth in placental insufficiency detected before 34th week's gestation

to evaluate the hypothesis that the fetal cerebroplacental ratio (CPR) is related to acidemia at birth in pregnancies complicated by placental insufficiency detected before 34 weeks of gestation. this is a prospective cohort study of 55 patients between 26 and 34 weeks of gestation with a diagnosis of placental insufficiency characterized by abnormal umbilical artery Doppler (pulsatility index>95 p). Fetal assessment was performed for each patient by dopplervelocimetry of the umbilical artery, middle cerebral artery and ductus venosus, and by the fetal biophysical profile. CPR was calculated using the ratio between middle cerebral artery pulsatility index and umbilical artery pulsatility index, and the z-score was obtained (number of standard deviations of the mean value at each gestational age). Acidemia at birth was characterized when pH<7.2. of 55 patients, 29 (52.7%) presented acidemia at birth. In the group of fetal acidemia, when compared with the group with pH>7.2, a significant association was observed with CPR values (median 0.47 versus 0.58; p=0.009), pulsatility index of the umbilical artery (median 2.45 versus 1.93; p=0.003), ductus venosus pulsatility index for veins (PIV) (median 1.08 versus 0.85; p=0.034) and suspected or abnormal fetal biophysical profile (37 versus 8%; p=0.031). CPR analysis by z-score showed a negative tendency, but was not statistically significant (p=0.080). Significant correlations were found between pH at birth and CPR (r=0.45; p<0.01), z-score of CPR (r=0.27; p<0.05) and ductus venosus PIV (r=-0.35 p<0.01). CPR is associated with the presence of acidemia at birth in pregnancies with placental insufficiency detected before 34 weeks of gestation and this parameter could potentially represent a factor for assessing the severity of fetal involvement.

Changes in umbilical venous volume flow after fetoscopic laser occlusion of placental vascular anastomoses in twin-to-twin transfusion syndrome

To examine effects of fetoscopic laser occlusion of placental vascular anastomoses on umbilical venous volume flow in twin-to-twin transfusion syndrome. Absolute umbilical venous volume flow, measured preoperatively and 48 hours after fetoscopic laser occlusion was related to Doppler studies, bladder filling in donors, and anastomoses. Among 45 patients, recipients had decreased ductus venosus pulsatility index (ductus venosus-pulsatility index for veins, 1.16 vs 1.01; P < .001) and unchanged umbilical venous volume flow after fetoscopic laser occlusion (74.7 vs 74.5 mL; P = .407). Donors had decreased umbilical artery pulsatility (1.34 vs 1.11; P = .008), increased ductus venous-pulsatility index for veins (0.75 vs 0.91; P < .014), and significantly increased umbilical venous volume flow per kilogram by 52.3% (136.6 vs 208.0 mL/Kg/min; P < .001). Donor bladder filling occurred at higher umbilical venous volume flow per kilogram (142.7 vs 221.4 mL/Kg/min; P < .012). Increase in umbilical venous volume flow per kilogram correlated with the net difference in arteriovenous anastomoses (Pearson r = 0.403, P = .006). Fetoscopic laser occlusion in twin-to-twin transfusion syndrome corrects intertwin differences in umbilical venous volume flow by predominant effects in the donor. Reappearance of donor bladder filling correlates with correction of volume flow.