Placental vascularization measured by three-dimensional power Doppler ultrasound at 11 to 13 + 6 weeks' gestation in normal and aneuploid fetuses

Ultrasound Microvessel Imaging of the Human Placenta Demonstrates Altered Vessel Densities in Fetal Growth Restriction With Vascular and Immune Pathologies: A Pilot Case-Control Study

OBJECTIVES

Fetal growth restriction (FGR) is commonly associated with placental dysfunction, increasing perinatal morbidity and mortality. Visualizing placental vessels in utero would be advantageous for identifying functional FGR cause and determining proper management strategies. We aimed to utilize high-sensitivity ultrasound microvessel imaging (HUMI) for quantifying placental vessel density (VD) in pregnancies diagnosed with FGR.

METHODS

This pilot case-control study enrolled subjects in the third trimester with a diagnosis of FGR (n = 40) and gestational age-matched controls with normal fetal growth (n = 20) at a 2:1 ratio, respectively. The Verasonics Vantage ultrasound system was used to perform HUMI on each participant at one timepoint. Scanning involved randomized singular value decomposition-based clutter filtering to identify the villous tree, followed by step-by-step scanning to acquire 3-dimensional-like data. Mean VD was calculated from three ultrasound measurements per subject. Additional clinical and pathology data were also collected and compared.

RESULTS

Sixteen participants were utilized to establish the scanning protocol and 2 met exclusion criteria at delivery. Thus, VD was successfully measured on 42 pregnancies scanned at 35 weeks 5 days on average. In FGR (n = 24), placental VD was significantly reduced compared to controls (P < .01). VD measures were as good at predicting FGR as systolic/diastolic (S/D) ratios (area under the curve 0.86 versus 0.80). In a smaller cohort, VD in placentas with a diagnosis of inflammatory villitis (n = 10) by histology showed an increase in VD compared to those without inflammation (P = .01). Low VD was correlated with increased S/D ratios (P = .03).

CONCLUSIONS

HUMI is useful for identifying altered placental vascularization in utero for FGR. VD may be a valuable indicator for placental health and could lead to improved risk stratification methods considering underlying biology.

The clinical value of combining shear wave elastography, VOCAL technique, and T2* MRI of early gestation placenta to predict pre-eclampsia

OBJECTIVE

To investigate the clinical value of combining shear wave elastography (SWE) with the Volumetric Organ Computer-Aided AnaLysis (VOCAL) technique and T2* magnetic resonance imaging (MRI) to predict pre-eclampsia (PE).

METHODS

From December 2022 to March 2023, we recruited 31 pregnant women diagnosed with PE at our hospital as the observation group and 85 normal pregnant women as the control group. Differences in placental elasticity, vascularization index (VI), flow index (FI), vascularization flow index (VFI), and T2* MRI perfusion fraction (f) were compared between the two groups. Received operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value of placental elasticity, VI, FI, VFI, f, and their combination for predicting PE.

RESULTS

Placental elasticity was higher in the observation group than in the control group, while VI, FI, VFI, and f were lower in the observation group (all p < 0.05). The area under the curve (AUC) for placental elasticity, VI, FI, VFI, f, and their combination for predicting PE were 0.85, 0.77, 0.78, 0.84, 0.65, and 0.94, respectively. The sensitivity was 71%, 55%, 94%, 65%, 55%, and 81%. The specificity was 92%, 91%, 60%, 92%, 79%, and 98%. The combined prediction model had a higher AUC than the individual predictors (p < 0.05).

CONCLUSION

SWE combined with VOCAL technique and T2* MRI has high value for predicting PE and can provide reference information for clinical diagnosis.

Umbilical artery pulsatility index and half-peak systolic velocity in second- and third-trimester fetuses with trisomy 18 and 13

OBJECTIVES

To analyze umbilical artery (UA) Doppler velocimetry and its possible role in placenta-mediated fetal growth restriction (FGR) in second- and third-trimester fetuses with trisomy 18 and 13.

METHODS

UA pulsatility index (PI) and half-peak systolic velocity deceleration time (hPSV-DT) were measured in fetuses with trisomy 18 and 13. Correlation with gestational age, birthweight, and perinatal outcome was analyzed.

RESULTS

A total of 80 measurements were taken from 33 fetuses with trisomy 18 and 19 with trisomy 13. Overall, there was a high prevalence of abnormal UA Doppler velocimetry. In fetuses with trisomy 18, 54% (27/50) of the UA PI values and 58% (29/50) of the UA hPSV-DT values were abnormal. In fetuses with trisomy 13, 80% (24/30) of the UA PI values and 87% (26/30) of the UA hPSV-DT values were abnormal. The prevalence of abnormal UA Doppler velocimetry increased with gestational age in both types of aneuploidy. However, this trend was only significant for trisomy 13 (p<0.05). All fetuses with trisomy 18 and 86% of fetuses with trisomy 13 were classified at birth as FGR. There were no perinatal survivors in this series.

CONCLUSIONS

A high prevalence of abnormal UA Doppler velocimetry was found in second- and third-trimester fetuses with trisomy 18 and 13, which further increased with gestational age. These results may well correlate with alterations described previously in the placenta, suggesting placental insufficiency has an important role in the development of FGR in these autosomal aneuploid fetuses.

MicroRNA-138 improves LPS-induced trophoblast dysfunction through targeting RELA and NF-κB signaling

Preeclampsia is a pregnancy complication classified by new onset of elevated blood pressure and proteinuria after 20 weeks of gestation. During preeclampsia, extra villous trophoblasts fail to adequately invade the myometrial spiral arteries, leading to incomplete and impaired vessel transformation and initiating or aggravating preeclampsia. Although NF-κB and proinflammatory cytokines have been reported to be related to trophoblast dysfunction, the underlying mechanism remains unclear. Herein, we demonstrated the miR-138/RELA axis modulating the migratory ability, and invasive ability of HTR-8/SVneo and JEG-3 cells, as well as the inflammatory factor levels in response to LPS stimulation. miR-138 expression was upregulated in preeclampsia placenta and LPS-stimulated HTR-8/SVneo and JEG-3 cell lines. miR-138 overexpression rescued the migratory and invasive ability of HTR-8/SVneo and JEG-3 cells inhibited by LPS stimulation, and decreased LPS-induced TNF-α and IL-6 levels. By binding the 3'-UTR of RELA, miR-138 negatively regulated p65 expression. The silencing of p65 also improved LPS-induced HTR-8/SVneo and JEG-3 cell dysfunction and TNF-α and IL-6 levels. More importantly, p65 overexpression partially reversed the functions of miR-138 overexpression upon both cells, indicating that miR-138 exerted its biological effects through targeting RELA. In conclusion, miR-138 improves LPS-induced inflammation and oxidative stress on trophoblasts through targeting RELA and affecting NF-κB signaling. The miR-138/RELA axis might be involved in preeclampsia pathogenesis, which requires further in vivo and clinical researches.

Uterine and placental blood flow indexes and antinuclear autoantibodies in unexplained recurrent pregnancy loss: should they be investigated in pregnancy as correlated potential factors? A retrospective study

BACKGROUND

The potential role of antinuclear antibodies (ANA) in recurrent pregnancy loss (RPL) pathogenesis is still debated, although some evidences suggest that they could affect pregnancy outcome, leading to a higher miscarriage rate in these patients. A hypothesized mechanism is through changes in uterine flow in pre-conceptional stage, by modifying endometrial receptivity in RPL. However, scant data are available, in pregnancy, about their role in RPL placental perfusion, also in relation to its potential treatments, such as low molecular weight heparin (LMWH). The aim of this study is to retrospectively further investigate the correlation between two-dimensional (2D) and three-dimensional (3D) uterine and placental flow indexes and the presence or the absence of ANA in women with unexplained RPL (uRPL), treated or not treated with LMWH.

METHODS

2D Doppler measurement of pulsatility index (PI) of the uterine arteries and 3D ultrasonography determination of vascularization index (VI), flow index (FI) and vascularization flow index (VFI) was carried out with the aid of the virtual organ computer-aided analysis (VOCAL) technique in LMWH treated (n 24) and not treated-uRPL patients (n 20) and in the relative control group (n 27), each group divided in ANA+ and ANA- subgroups. Serum assay for the presence of ANA was performed in all women.

RESULTS

No differences were found in PI, VFI and VI values, by comparing the different groups. A difference in VI values was found for ANA- patients between RPL women not treated with LMWH and the treated ones (p = 0,01), which have lower VI values and similar to controls. By considering only ANA- treated and not treated RPL patients, the ROC curve shows an area of 0,80 and at the VI cut-off of 11,08 a sensitivity of 85% and a specificity of 67%.

CONCLUSIONS

LMWH could exert a potential beneficial effect in restoring the physiological blood flow supply in terms of VI in uRPL ANA- status, suggesting to include ANA and VI investigations in the RPL diagnostic algorithm in a research context, since further studies are needed to clarify this challenging hypothesis in order to try to ameliorate ANA and abnormal placental vascularization negative influence on RPL pregnancy outcome .

Three-dimensional power Doppler ultrasound evaluation of placental blood flow in normal monochorionic diamniotic twin pregnancies

Background

Monochorionic diamniotic (MCDA) twin pregnancies are at higher risk of adverse outcomes and complications, which are attributed to the influence of placental morphology in MCDA twins. Monitoring of placental function is an important index for clinical decisions. The aim of our study was to evaluate the placental blood flow estimated using three-dimensional power Doppler (3D-PD) ultrasound and the vascular indices distribution with gestational age (GA) in normal MCDA twin pregnancies.

Methods

One hundred four MCDA twin pregnancies and 106 singleton pregnancies (GA range, 14–32 weeks) were included in this prospective study. 3D-PD volume data of each fetus was obtained separately from the placenta at the site of umbilical cord insertion. We analyzed the volume data using sonobiopsy technique. The placental vascularization index (VI), flow index (FI) and vascularizationflow index (VFI), were auto-calculated. The means and standard deviation values of three vascular indices per fetus were calculated and regression analysis of the vascular indices as a function of GA was performed in twin pregnancies. The vascular indices of twin and singleton pregnancies were compared using independent t-test.

Results

There were no significant differences in VI, FI or VFI among the fetuses of twins (p > 0.05). These vascular indices increased over the course of pregnancy (p < 0.05). We obtained the regression equations for the indices as a function of GA in days: VI = exp. (4.369–28.533/GA) (R² = 0.699, p < 0.05), FI = exp. (3.916–13.003/GA) (R² = 0.511, p < 0.05), and VFI = exp. (3.577–37.468/GA) (R² = 0.675, p < 0.05). There were no significant differences in three vascular indices between MCDA twin and singleton groups (p > 0.05).

Conclusions

3D-PD placental data using sonobiopsy technique could reflect the placental blood flow of each twin, which could be applied to the study of placental perfusion in MCDA twin pregnancies. This study also presented the vascular indices distribution with GA in normal twin pregnancies, which might be useful for early detection of MCDA complications.

Effect of chorionic villus sampling on placental volume and vascularization in the first trimester of pregnancy

Objective: To evaluate the effects of chorionic villus sampling (CVS) on placental volume (PV), perfusion, and vasculature in the first trimester of pregnancy.Method: Uterine artery pulsatility index (PI), PV, vascularization index (VI), flow index (FI), and Vascularization Flow Index (VFI) were serially measured in 38 pregnant women who underwent CVS. Thirty-eight women who did not undergo invasive prenatal diagnosis were recruited as controls.Results: CVS was associated with a mild reduction of PI, a reduction of placental VI, FI, and VFI and with an increase in PV detected one week after the procedure. The outcome of pregnancy was similar between women of the two groups.Conclusion: Our findings showed that CVS is associated with mild placental vascular and morphological changes. However, these changes do not seem to be associated with adverse outcome.

Can 3-dimensional power Doppler indices improve the prenatal diagnosis of a potentially morbidly adherent placenta in patients with placenta previa?

BACKGROUND

Traditionally, 2-dimensional ultrasound parameters have been used for the diagnosis of a suspected morbidly adherent placenta previa. More objective techniques have not been well studied yet.

OBJECTIVE

The objective of the study was to determine the ability of prenatal 3-dimensional power Doppler analysis of flow and vascular indices to predict the morbidly adherent placenta objectively.

STUDY DESIGN

A prospective cohort study was performed in women between 28 and 32 gestational weeks with known placenta previa. Patients underwent a two-dimensional gray-scale ultrasound that determined management decisions. 3-Dimensional power Doppler volumes were obtained during the same examination and vascular, flow, and vascular flow indices were calculated after manual tracing of the viewed placenta in the sweep; data were blinded to obstetricians. Morbidly adherent placenta was confirmed by histology. Severe morbidly adherent placenta was defined as increta/percreta on histology, blood loss >2000 mL, and >2 units of PRBC transfused. Sensitivities, specificities, predictive values, and likelihood ratios were calculated. Student t and χ² tests, logistic regression, receiver-operating characteristic curves, and intra- and interrater agreements using Kappa statistics were performed.

RESULTS

The following results were found: (1) 50 women were studied: 23 had morbidly adherent placenta, of which 12 (52.2%) were severe morbidly adherent placenta; (2) 2-dimensional parameters diagnosed morbidly adherent placenta with a sensitivity of 82.6% (95% confidence interval, 60.4-94.2), a specificity of 88.9% (95% confidence interval, 69.7-97.1), a positive predictive value of 86.3% (95% confidence interval, 64.0-96.4), a negative predictive value of 85.7% (95% confidence interval, 66.4-95.3), a positive likelihood ratio of 7.4 (95% confidence interval, 2.5-21.9), and a negative likelihood ratio of 0.2 (95% confidence interval, 0.08-0.48); (3) mean values of the vascular index (32.8 ± 7.4) and the vascular flow index (14.2 ± 3.8) were higher in morbidly adherent placenta (P < .001); (4) area under the receiver-operating characteristic curve for the vascular and vascular flow indices were 0.99 and 0.97, respectively; (5) the vascular index ≥21 predicted morbidly adherent placenta with a sensitivity and a specificity of 95% (95% confidence interval, 88.2-96.9) and 91%, respectively (95% confidence interval, 87.5-92.4), 92% positive predictive value (95% confidence interval, 85.5-94.3), 90% negative predictive value (95% confidence interval, 79.9-95.3), positive likelihood ratio of 10.55 (95% confidence interval, 7.06-12.75), and negative likelihood ratio of 0.05 (95% confidence interval, 0.03-0.13); and (6) for the severe morbidly adherent placenta, 2-dimensional ultrasound had a sensitivity of 33.3% (95% confidence interval, 11.3-64.6), a specificity of 81.8% (95% confidence interval, 47.8-96.8), a positive predictive value of 66.7% (95% confidence interval, 24.1-94.1), a negative predictive value of 52.9% (95% confidence interval, 28.5-76.1), a positive likelihood ratio of 1.83 (95% confidence interval, 0.41-8.11), and a negative likelihood ratio of 0.81 (95% confidence interval, 0.52-1.26). A vascular index ≥31 predicted the diagnosis of a severe morbidly adherent placenta with a 100% sensitivity (95% confidence interval, 72-100), a 90% specificity (95% confidence interval, 81.7-93.8), an 88% positive predictive value (95% confidence interval, 55.0-91.3), a 100% negative predictive value (95% confidence interval, 90.9-100), a positive likelihood ratio of 10.0 (95% confidence interval, 3.93-16.13), and a negative likelihood ratio of 0 (95% confidence interval, 0-0.34). Intrarater and interrater agreements were 94% (P < .001) and 93% (P < .001), respectively.

CONCLUSION

The vascular index accurately predicts the morbidly adherent placenta in patients with placenta previa. In addition, 3-dimensional power Doppler vascular and vascular flow indices were more predictive of severe cases of morbidly adherent placenta compared with 2-dimensional ultrasound. This objective technique may limit the variations in diagnosing morbidly adherent placenta because of the subjectivity of 2-dimensional ultrasound interpretations.

Role of 3-D ultrasound in clinical obstetric practice: evolution over 20 years

The use of 3-D ultrasound in obstetrics has undergone dramatic development over the past 20 years. Since the first publications on this application in clinical practice, several 3-D ultrasound techniques and rendering modes have been proposed and applied to the study of fetal brain, face and cardiac anatomy. In addition, 3-D ultrasound has improved calculations of the volume of fetal organs and limbs and estimations of fetal birth weight. And furthermore, angiographic patterns of fetal organs and the placenta have been assessed using 3-D power Doppler ultrasound quantification. In this review, we aim to summarize current evidence on the clinical relevance of these methodologies and their application in obstetric practice.

Are there any differences in three-dimensional placental vascular indices obtained using conventional power Doppler and high-definition flow imaging?

OBJECTIVE

The purpose of this study was to determine whether there are differences in values and reproducibility of three-dimensional (3D) vascular indices obtained on placental volumes using power Doppler (PD) or high-definition flow imaging (HDFI) techniques.

METHODS

A prospective study was performed on 121 uncomplicated singleton pregnancies at 11 + 0 to 13 + 6 weeks of gestation. Two placental volumes were acquired from each pregnancy. Vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were then analyzed and compared. In order to assess the reproducibility of the measurements, two additional placental volumes obtained with both PD and HDFI were acquired in 31 pregnancies and the agreement assessed by intraclass correlation coefficients. Inter-observer variability was assessed by analyzing all the volumes by two observers blinded to each other's.

RESULTS

A significant relationship was observed between the vascular indices values obtained with the two techniques (VI Pearson's r=0.891 p<0.001; FI r=0.769 p<0.001; VFI r=0.847 p<0.001). The median values of VI, FI and VFI were significantly higher when obtained with HDFI imaging. In serial recordings, the ICCs resulted higher when volumes were acquired with HDFI rather than with PD techniques. Similarly, HDFI demonstrated a higher inter-observer reproducibility.

CONCLUSIONS

3D vascular indices calculated using HDFI are higher than those calculated using conventional PD. Although the relationship between the two methods is high, HDFI shows a better reproducibility suggesting its potential clinical application.

First trimester placental volume and three dimensional power doppler ultrasonography in type I diabetic pregnancies

OBJECTIVE

This study aimed to investigate the placental volume and three dimensional (3D) power Doppler vascularization in type I diabetic pregnancies during the first trimester

METHODS

3D-power Doppler ultrasonography of the placenta was performed at 11+0-13+6 weeks in 32 pregnancies complicated by type I diabetes. Placental volume, vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were calculated using a standardized setting.

RESULTS

In nine pregnancies, a poor first trimester glycemic control was present as expressed by HbA1c levels  ≥ 7%, whereas in the remaining 23 mothers, the HbA1c concentrations were <7%. No differences were found in the placental volumes of diabetic mothers when compared with reference limits. 3D Doppler placental vascular indices were significantly higher in diabetic mothers (VI delta value 0.99, p=0.0012; FI delta value 0.64, p=0.0008; VFI delta value 1.28, p=0.0039) when compared with reference limits. Pregnancies with HbA1c ≥ 7% exhibited higher placental vascular indices when compared with diabetic mothers with better glycemic control.

CONCLUSIONS

In type I diabetic mothers, placental vascular indices are increased and these modifications are more evident in pregnancies with poor first trimester glycemic control.

Imaging and assessment of placental function

The placenta is the vital support organ for the developing fetus. This article reviews current ultrasound (US) methods of assessing placental function. The ability of ultrasound to detect placental pathology is discussed. Doppler technology to investigate the fetal, placental, and maternal circulations in both high-risk and uncomplicated pregnancies is discussed and the current literature on the value of three-dimensional power Doppler studies to assess placental volume and vascularization is also evaluated. The article highlights the need for further research into three-dimensional ultrasound and alternative methods of placental evaluation if progress is to be made in optimizing placental function assessment.

Histomorphometric characteristics of first trimester chorionic villi in pregnancies with low serum pregnancy-associated plasma protein-A levels: relationship with placental three-dimensional power doppler ultrasonographic vascularization

OBJECTIVE

To evaluate histomorphometric vascular characteristics from samples obtained by chorionic villus sampling (CVS) in pregnancies with low serum pregnancy-associated plasma protein-A (PAPP-A) levels and to relate these findings to three-dimensional (3D) placental volume and power Doppler vascularization.

METHODS

Immediately before CVS, placental 3D-power Doppler ultrasonography was performed at 11 + 0 to 13 + 6 weeks in 12 pregnancies with PAPP-A concentrations <0.3 multiples of median (MoM) as well as in 11 control women. Using a standardized setting placental volume, vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were measured. Histomorphometric parameters of villi were blindly evaluated with a video-computerized-image-analysis system.

RESULTS

Pregnancies with low PAPP-A showed a significantly reduced number of capillary vessels per villus cross-section (p = 0.005) and a smaller capillary diameter (p = 0.041). Placental vascular indices were significantly related to the number of fetal capillary vessels per villus (VI: r = 0.51, p = 0.03; FI: r = 0.48, p = 0.04; VFI: r = 0.56, p = 0.01).

CONCLUSIONS

Differences in placental vascularization are present in first trimester in pregnancies with low PAPP-A and they are associated to altered 3D placental Doppler indices.

Prenatal sonographic features of fetuses in trisomy 13 pregnancies. IV

Prenatal ultrasound is a powerful tool to detect structural abnormalities associated with the fetuses in trisomy 13 pregnancies. This article provides a comprehensive review of the prenatal sonographic markers of trisomy 13 in the first trimester, including fetal nuchal translucency thickness, fetal heart rate, fetal nasal bone, fetal tricuspid regurgitation, ductus venous flow, fetal crown-rump length, fetal trunk and head volume, fetal frontomaxillary facial angle, gestational sac volume and umbilical cord diameter, along with biochemical markers such as maternal serum free beta-human chorionic gonadotropin, maternal serum pregnancy-associated plasma protein-A, maternal serum placental growth factor, and the fetal and total cell-free DNA concentration in the maternal circulation.

Reproducibility of regional placental vascularity/perfusion measurement using 3D power Doppler

OBJECTIVES

To assess reproducibility and regional variability of placental perfusion measurement using three-dimensional (3D) power Doppler VOCAL() (Virtual Organ Computer-aided AnaLysis).

METHODS

Twenty pregnant women at 26-34 weeks' gestation with normally grown, biophysically normal, singleton pregnancies with anterior placentae had placental power Doppler mapping data stored digitally from each of the four placental quadrants. Each was imaged by two investigators, with two datasets stored per investigator per quadrant. 5760 data values from the 320 datasets were evaluated by the same two investigators. Power Doppler imaging of the placental cord insertion was performed to generate a value for standardization as 'fractional moving blood volume' if appropriate. The vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated from spherical regions-of-interest to assess reproducibility within and between quadrants and between investigators for both acquisition and analysis.

RESULTS

We found extensive variability for all readings. For repeated measurements within the same dataset the intra-analyzer intraclass correlation coefficient (ICC) range was: 0.24-0.57 for VI, 0.33-0.78 for FI and 0.12-0.48 for VFI. The corresponding interanalyzer ICC range was: 0.38-0.92 for VI, 0.40-0.85 for FI and 0.10-0.92 for VFI. The intra-acquirer variability (paired t-test) mean differences range was: - 3.91 to 4.71 for VI, - 2.68 to 3.31 for FI and - 2.23 to 2.78 for VFI; the corresponding interacquirer variability (paired t-test) range was: - 1.92 to 5.18 for VI, - 3.06 to 2.04 for FI and - 1.69 to 2.60 for VFI. The regional variability range (coefficient of variation) was: 6.28-126.34% for VI, 2.26-49.01% for FI and 6.09-151.55% for VFI. For all analyzed data, FI showed least variability and cord values for VI were consistently 100% (mean VFI, 98.4 and 98.8 between observers).

CONCLUSIONS

There is insufficient evidence to support the meaning, reliability or reproducibility of VOCAL (VI, FI or VFI) as a tool to quantify placental perfusion, despite its use in multiple publications and journal submissions. There is poor reproducibility at the most fundamental level. Further investigation into the reproducibility of placental perfusion and quantification using VOCAL is required before development and application as a clinically useful tool.

Reprodutibilidade interobservador dos índices vasculares do Doppler de amplitude tridimensional do embrião entre 7 e 10 semanas e 6 dias de gestação

OBJETIVO: Avaliar a reprodutibilidade interobservador dos índices de vascularização do Doppler de amplitude tridimensional (Doppler de amplitude 3D) no primeiro trimestre de gestação. MATERIAIS E MÉTODOS: Realizou-se estudo de reprodutibilidade com 32 gestantes normais entre 7 e 10 semanas e 6 dias. Para o cálculo do volume tridimensional dos embriões utilizou-se o método VOCAL (Virtual Organ Computer-aided AnaLysis) com ângulo de rotação de 12°. Em seguida obtiveram-se, automaticamente, os três índices vasculares do Doppler de amplitude 3D: índice de vascularização (VI), índice de fluxo (FI) e índice de vascularização e fluxo (VFI). Para o cálculo da variabilidade interobservador, um examinador realizou uma segunda medida dos 32 embriões e um segundo examinador realizou uma terceira medida dos mesmos volumes, ambos desconhecendo os resultados do outro. Utilizaram-se, para análise estatística, o coeficiente de correlação intraclasse (CCI) e gráficos de Bland-Altman. RESULTADOS: Observou-se boa reprodutibilidade interobservador dos três índices vasculares. O VI apresentou CCI = 0,9 e média da diferença = -1,1; o FI apresentou CCI = 0,9 e média da diferença = -0,5; e o VFI apresentou CCI = 0,9 e média da diferença = -1,1. CONCLUSÃO: Os índices vasculares do Doppler de amplitude 3D do embrião no primeiro trimestre de gestação foram altamente reprodutíveis, em especial o FI.

Umbilical vein blood flow at 11 + 0 to 13 + 6 weeks of gestation

OBJECTIVE

To establish reference intervals for fetal umbilical vein (UV) diameter, UV time averaged maximum velocity (TAMXV) and UV flow (UVBF) at 11 + 0 to 13 plus; 6 weeks of gestation and to determine the intraobserver reliability of these measurements.

METHODS

We considered, in a cross-sectional study, 162 fetuses from uncomplicated singleton pregnancies at 11 + 0 to 13 + 6 weeks of gestation. UV diameter and TAMXV were measured in its intraabdominal portion by real-time and Doppler ultrasonography and UVBF calculated. Relationships between these parameters and fetal crown rump length were tested by regression analysis. In 25 cases UVBF was measured twice by the same investigator and the intraobserver agreement of these measurements was calculated.

RESULTS

A significant increase was evidenced in the gestational age period considered in UV diameter (r = 0.729, p < 0.0001), TAMXV (r = 0.691, p < 0.0001) and UVBF (r = 0.777, p < 0.0001). UVBF increased from 2.26 ml/min at 11 weeks to 15.62 ml/min at 13 + 6 weeks of gestation. The intraobserver ICCs were 0.96, 0.92 and 0.88, respectively, for UV diameter, TAMXV and UVBF.

CONCLUSIONS

In normal fetuses, UV diameter, TAMVX and flow increase between 11 + 0 and 13 + 6 weeks of gestation. In this gestational age interval, the calculation of UV blood flow and its components shows an intraobserver agreement reliable enough for clinical use.

First-trimester placental volume and vascularization measured by 3-dimensional power Doppler sonography in pregnancies with low serum pregnancy-associated plasma protein a levels

OBJECTIVE

The purpose of this study was to investigate the first-trimester placental volume and 3-dimensional (3D) power Doppler vascularization of pregnancies with low serum pregnancy-associated plasma protein A (PAPP-A) levels and to relate these findings to pregnancy outcomes.

METHODS

Three-dimensional power Doppler sonography of the placenta was performed at gestational ages of 11 weeks to 13 weeks 6 days in 84 pregnancies with PAPP-A concentrations of less than 0.4 multiple of the median (MoM). With a standardized setting, the placental volume and vascularization index (VI), flow index (FI), and vascularization-flow index (VFI) were calculated and related to pregnancy outcomes.

RESULTS

Pregnancy outcomes were as follows: 57 pregnancies with birth weights at or above the 10th percentile (group A), 16 pregnancies with birth weights below the 10th percentile and normal Doppler findings in the umbilical artery throughout gestation (group B), and 11 pregnancies with birth weights below the 10th percentile and abnormal umbilical Doppler findings later in gestation (group C). No differences were found in PAPP-A levels among groups. Placental volume values were significantly lower than reference limits, but no differences were found between groups. In groups A and B, there were no significant differences in 3D Doppler indices. However, these indices were significantly lower in group C (VI mean difference, -1.904; P < .001; FI mean difference, -1.939; P < .001; VFI mean difference, -1.944; P < .001). Placental vascular indices were significantly related to the severity of intrauterine growth restriction (IUGR; VI, r = 0.438; P < .001; FI, r = 0.482; P < .001; VFI, r = 0.497; P < .001) but not to the PAPP-A MoM and placental volume values.

CONCLUSIONS

Low serum maternal PAPP-A levels are associated with altered 3D placental Doppler indices, and these changes are related to subsequent development of IUGR and adverse pregnancy outcomes.

Embryo vascularization by three-dimensional power Doppler ultrasonography at 7-10 weeks of pregnancy

AIM

Assess vascular indices of 7-10 week embryos using three-dimensional power Doppler (3DPD) and correlate them with the crown-rump length (CRL).

METHODS

This cross-sectional study included 65 healthy pregnancies between 7 and 10 weeks. The three-dimensional volume of the embryo was obtained using an endocavitary volumetric transducer and the VOCAL (Virtual Organ Computer-aided Analysis) method, with a 12 degree rotation angle and 15 sequential planes. The vascularization (VI), flow (FI) and the vascular and flow (VFI) indices were obtained using 3DPD and the mean, median, standard deviation, maximum and minimum values were calculated for each gestational age. Pearson's correlation coefficient (r) was used to evaluate the correlation between vascular indices and CRL.

RESULTS

The VI ranged from 0.77 to 41.67, mean 14.68 (+/-8.60), the FI went from 25.71 to 139.50, mean 90.61 (+/-21.51) and the VFI from 0.20 to 81.57, mean 15.69 (+/-12.42). The correlation between CRL and all 3D power Doppler vascular indices was low (VI - r=-0.073, P=0.566; FI - r=0.173, P=0.168 and VFI - r=-0.004, P=0.974).

CONCLUSION

3D power Doppler vascular indices in 7-10 week embryos do not correlate with CRL.

Effects of maternal cigarette smoking on placental volume and vascularization measured by 3-dimensional power Doppler ultrasonography at 11+0 to 13+6 weeks of gestation

OBJECTIVE

We sought to establish the effect of maternal smoking on placental volume and vascularization in early gestation.

STUDY DESIGN

Three-dimensional power Doppler ultrasonography of the placenta was performed at 11+0 to 13+6 weeks in 80 pregnancies categorized according to cigarette consumption: group A never smoked, B smoking < 10 cigarettes/day, C smoking 10-20 cigarettes/day, and D smoking > 20 cigarettes/day. Using a standardized setting, placental volume and vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were calculated.

RESULTS

No differences were found in placental volume among groups. In groups C and D lower values were found for VI (group C: t = 4.52, P = .0002; group D: t = 3.72, P = .0014), FI (group C: t = 5.06, P = .0001; group D: t = 4.59, P = .0002), and VFI (group C: t = 3.49, P = .0024; group D: t = 2.88, P = .0095). Placental vascular indices were significantly related to birthweight (VI r = 0.563, FI r = 0.580, VFI r = 0.601; P < .001).

CONCLUSION

Maternal smoking is associated with altered 3-dimensional placental Doppler indices and these changes are related to birth weight.

Intervillous and uteroplacental circulation in normal early pregnancy and early pregnancy loss assessed by 3-dimensional power Doppler angiography

OBJECTIVE

To assess intervillous and uteroplacental circulation in early normal pregnancies and miscarriages.

STUDY DESIGN

One hundred normal pregnancies and 46 delayed miscarriages were evaluated by 3-dimensional vaginal ultrasound and power Doppler angiography. Volumes of the early placenta and the subplacental area were obtained between 5 and 12.6 weeks' gestation. The placental volume, vascularization index, flow index, and vascularization flow index was calculated.

RESULTS

Intraclass correlation coefficients ranged from 0.961 for placental volume to 0.885 for intervillous flow index. Intervillous power Doppler signals were not detected before the sixth week. Placental volume (R(2) = 0.68), intervillous vascularization index (R(2) = 0.30), flow index (R(2) = 0.33) and vascularization flow index (R(2) = 0.35), uteroplacental flow index (R(2) = 0.34), and vascularization flow index (R(2) = 0.17) increase significantly (P < .001) throughout the first trimester of normal pregnancies. Uteroplacental vascularization index was not significantly related to gestational age. Intervillous vasculariztion index, flow index, and vascularization flow index were significantly raised in miscarriages, but there were no significant differences for uteroplacental vascularization index, flow index, or vascularization flow index.

CONCLUSION

Intervillous and uteroplacental blood flow increases throughout the first trimester of normal pregnancies. Intervillous circulation is abnormally increased when a miscarriage is diagnosed.