Three-dimensional power Doppler indices at 18–22 weeks’ gestation for prediction of fetal growth restriction or pregnancy-induced hypertension

A longitudinal and cross-sectional study of placental circulation between normal and placental insufficiency pregnancies

INTRODUCTION

To longitudinally and cross-sectionally study the differences in the uterine artery pulsatility index (UTPI), umbilical artery pulsatility index (UAPI) and placental vascularization indices (PVIs, derived from 3-dimensional power Doppler) between normal and placental insufficiency pregnancies throughout gestation.

METHODS

UTPI, UAPI and PVI were measured 6 times at 4- to 5- week intervals from 11 to 13+6 weeks-36 weeks. Preeclampsia (PE) and fetal growth restriction (FGR) were defined as placental insufficiency. Comparisons of UTPI, UAPI and PVI between normal and insufficiency groups were performed by one-way repeated measures analysis of variance.

RESULTS

A total of 125 women were included: monitored regularly from the first trimester to 36 weeks of gestation: 109 with normal pregnancies and 16 with placental insufficiency. Longitudinal study of the normal pregnancy group showed that UTPI and UAPI decreased significantly every 4 weeks, while PVIs increased significantly every 8 weeks until term. In the placental insufficiency group however, this decrease occurred slower at 8 weeks intervals and UTPI stabilized after 24 weeks. No significant difference was noted in PVIs throughout pregnancy. Cross-sectional study from different stages of gestation showed that UTPI was higher in the insufficiency group from 15 weeks onward and PVIs were lower after 32 weeks.

DISCUSSION

Compared to high-risk pregnancies with normal outcome, UTPI and UAPI needed a longer time to reach a significant change in those with clinical confirmation of placental insufficiency pregnancies and no significant change was found in PVI throughout gestation. UTPI was the earliest factor in detecting adverse outcome pregnancies.

The Application Value of Three-Dimensional Power Doppler Ultrasound in Fetal Growth Restriction

In this study, the application value of three-dimensional power Doppler ultrasound (3D-PDU) in fetal growth restriction (FGR) is explored. The retrospective cohort study enrolled pregnant women (with a gestational week of 11–13 + 6 weeks) who received routine health care in the obstetrics and gynecology clinic of our hospital from January 2020 to January 2021. The placentae were scanned using 3D-PDU, and the subjects were followed up until delivery. The fetuses were divided into the control group (n = 322) and FGR group (n = 44) according to their birth weight. There was no significant difference in nuchal translucency (NT), crown-rump length (CRL), and placental volume (PV) during the first trimester between the two groups (P > 0.05). Compared with the control group, the FGR group showed significantly lower levels of vascularisation index (VI), flow index (FI), and vascularisation flow index (VFI) and a higher incidence of fetal distress and neonatal asphyxia (P < 0.05). The FGR group showed a longer gestational week at birth, a higher probability of cesarean section, and a lower 5-minute Apgar score than the control group (P < 0.05). The VI, FI, and VFI of the control group were significantly higher than those of the FGR group. Pearson analysis showed that birth weight was positively correlated with VI and FI (P < 0.05). 3D-PDU assesses the blood perfusion of the fetus and placenta in the first trimester and predicts the pregnancy outcome, which shows great potential in the early diagnosis of FGR.

New insights into human functional ultrasound imaging

Ultrasound imaging is a vital tool for exploring in vivo the placental function which is essential to understand pathological phenomena such as preeclampsia or intrauterine growth restriction. As technology advances including ready availability of three-dimensional (3D) probes and novel software, new markers of placental function become possible. The objective of this review was to provide an overview of the new ultrasound markers of placental function with a focus on the potential clinical application of three-dimensional power Doppler (3DPD). A broad-free text literature search was undertaken based on human placental studies and sixty full-text studies were included in this review. Three-dimensional power Doppler is a promising technique to predict preeclampsia in the first trimester. However, the influence of external factors such as body mass index, parameter standardisation and machine settings still need to be addressed. Contrast-enhanced ultrasound is currently reserved for research, because the required injected contrast mediums are not currently approved for use in pregnancy, although the safety data is reassuring.

Diagnostic value of 3D power Doppler ultrasound in the characterization of thyroid nodules

Background/aim

This study aimed to evaluate the diagnostic value of vascular indices obtained using 3D power Doppler ultrasound (3D PDUS) in differentiation of benign and malignant thyroid nodules.

Materials and methods

Sixty-seven patients (56 female, 11 male, mean age 44.6) with 81 thyroid nodules exhibiting mixed (peripheral and central) vascularization patterns, with the largest diameter between 10 and 30 mm, were prospectively evaluated using 3D PDUS. Nodule volume, vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were calculated using the Virtual Organ Computer-aided Analysis (VOCAL) software, and these indices were then compared with regard to the cytohistopathology-based diagnosis. The optimum cutoff values for the differentiation of benign and malignant nodules were identified, and diagnostic efficacy was calculated using receiver operating characteristic (ROC) analysis.

Results

Fifty-six of the 81 nodules included in this study were diagnosed as benign and 25 as malignant. Vascular indices in malignant nodules were significantly higher than those in benign nodules (P < 0.05). In benign nodules, the mean VI was 11.61 ± 6.88, mean FI was 39.75 ± 3.93, and mean VFI was 4.82 ± 2.94, compared to 18.64 ± 12.81, 41.82 ± 4.43, and 8.17 ± 6.37, respectively, in malignant nodules. The area under the curves (AUCs) was calculated as 0.68, 0.61, and 0.67 for VI, FI, and VFI, respectively. At optimal cutoff values of 10.2 for VI, 40.8 for FI, and 5.5 for VFI, the sensitivity and specificity were 72%/55.4%, 68%/57.1%, and 68%/67.9%, respectively.

Conclusion

3D PDUS can be useful in the characterization of thyroid nodules.

Placental Pulsatility: Quantitative Assessment of Placental Bed Vasculature by 2-Dimensional Doppler Cine Imaging

OBJECTIVES

Vascular resistance is known to be one of the determinants of pulsatile flow. This study aimed to investigate whether quantitative 2-dimensional Doppler ultrasound can capture and evaluate the pulsatility within the placental bed vasculature.

METHODS

The placental bed vasculature was imaged by directional power Doppler ultrasound. Ten-second cine clips were recorded by using standardized machine settings. A region of interest with a prominent Doppler signal in the uteroplacental interface was analyzed for the percentage of vascularity to generate a time-vascularity waveform. A vascular pulsatility index representing variation over the cardiac cycle was calculated by the ratio of the systolic-diastolic difference in vascularity to the mean vascularity. The acquisitions were repeated with 6 different pulse repetition frequencies (PRFs) and 3 wall motion filter (WMF) settings to evaluate their impact on the Doppler measurements.

RESULTS

Ten sets of cine clips were analyzed for this study. The pulsatile nature of the vascularity was readily apparent in each cine clip. The measured time-vascularity waveforms showed uniform cyclic variation in vascularity over the cardiac cycle, with systolic vascularity significantly higher than diastolic vascularity at each combination of PRF and WMF (P < .05). A gradual increase in the vascular pulsatility index was observed with an increasing PRF or WMF. Normalization of systolic-to-diastolic measurement provided a stable vascular assessment across the range of PRFs.

CONCLUSIONS

Doppler cine clips provide a dynamic representation of the placental bed vasculature and a novel analytic approach to quantitatively evaluating the pulsatility of this critical vascular network. Further work is warranted to explore the reproducibility and clinical potential of this approach.

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.

Maternal serum homocysteine and uterine artery Doppler as predictors of preeclampsia and poor placentation

PURPOSE

The aim of this study was to evaluate the role of maternal serum total Homocysteine (tHcy) and uterine artery (Ut-A) Doppler as predictors of preeclampsia (PE), intrauterine growth restriction (IUGR), and other complications related to poor placentation.

PATIENTS AND METHODS

A prospective cohort study was conducted on 500 women with spontaneous pregnancies. tHcy was measured at 15-19 weeks, and then, Ut-A Doppler was performed at 18-22 weeks of pregnancy.

RESULTS

453 pregnant women completed the follow-up of the study. The tHcy and Ut-A resistance index were significantly higher in women who developed PE, IUGR, and other complications when compared to controls (tHcy: 7.033 ± 2.744, 6.321 ± 3.645, and 6.602 ± 2.469 vs 4.701 ± 2.082 μmol/L, respectively, p value <0.001 and Ut-A resistance index: 0.587 ± 0.072, 0.587 ± 0.053, and 0.597 ± 0.069 vs 0.524 ± 0.025, respectively, p value <0.001). The use of both tHcy assessment and Ut-A Doppler improved the sensitivity of prediction of PE relative to the use of each one alone (85.2 relative to 73.33 and 60%, respectively).

CONCLUSION

The use of elevated homocysteine and uterine artery Doppler screening are valuable in prediction of preeclampsia, IUGR, and poor placentation disorders. CLINCALTRIAL.

GOV ID

NCT02854501.

3D power Doppler ultrasound assessment of placental perfusion during uterine contraction in labor

INTRODUCTION

To assess placental perfusion during spontaneous or induced uterine contraction in labor at term using placental vascular sonobiopsy (PVS) by 3D power Doppler ultrasound with the VOCAL imaging analysis program.

METHOD

PVS was performed in 50 normal pregnancies (32 in spontaneous labor group [SLG], and 18 in induced labor group with oxytocin or prostaglandin F2α [ILG]) at 37-41 weeks of gestation to assess placental perfusion during uterine contraction in labor. Only pregnancies with an entirely visualized anterior placenta were included in the study. Data acquisition was performed before, during (at the peak of contraction), and after uterine contraction. 3D power Doppler indices such as the vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were calculated in each placenta.

RESULTS

There were no abnormal fetal heart rate tracings during contraction in either group. VI and VFI values were significantly reduced during uterine contraction in both groups (SLG, -33.4% [-97.0-15.2%], and ILG, -49.6% [-78.2--4.0%]), respectively (P < 0.001). The FI value in the ILG group was significantly lower during uterine contraction (P = 0.035), whereas it did not change during uterine contraction in the SLG group. After uterine contraction, all vascular indices returned almost to the same level as that before uterine contraction. However, the FI value in ILG (-8.6%, [-19.7-16.0%]) was significantly lower than that in SLG (2.4%, [-13.4-38.1%]) after uterine contraction (P < 0.05). All 3D power Doppler indices (VI, FI, and VFI) during uterine contraction (at the peak of contraction) showed a correlation greater than 0.7, with good intra- and inter-observer agreements.

DISCUSSION

Our findings suggest that uterine contraction in both spontaneous and induced labors causes a significant reduction in placental perfusion. Reduced placental blood flow in induced uterine contraction has a tendency to be marked compared with that in spontaneous uterine contraction. To the best of our knowledge, this is the first study on the non-invasive assessment of placental perfusion during uterine contraction in labor using 3D power Doppler ultrasound. However, the data and their interpretation in the present study should be taken with some degree of caution because of the small number of subjects studied. Further studies involving a larger sample size are needed to assess placental perfusion and vascularity using PVS during normal and abnormal uterine contractions in normal and high-risk pregnancies.

Maternal plasma TIMP-4 levels combined with clinical risk factors for the early prediction of pregnancy-induced hypertension

OBJECTIVE

The objective of this study was to create a model for early predicting pregnancy-induced hypertension (PIH) using plasma markers and clinical risk factors.

METHODS

A nested case-control study was performed at the Laboratory Department of Guangzhou Women and Children's Medical Center. From a prospective cohort of tens of thousands of unselected women with singleton pregnancies at 8-20 weeks gestation, maternal plasma samples were obtained from 73 women who subsequently developed PIH (PIH group) and 146 gestational age- and maternal age-matched women with normotensive pregnancies (control group). Proteins extracted from the plasma samples were screened by microchip and verified by ELISA. Clinical risk factor data were analyzed retrospectively.

RESULTS

Compared to the control group, high concentrations of tissue inhibitor of metalloproteinase-4 (TIMP-4) were found in women with PIH (P = 0.000). Univariate risk factor analysis identified three variables with significant differences between the groups: family history of PIH (P = 0.031), body mass index (BMI; P < 0.001), and non-glucose-6-phosphate dehydrogenase deficiency-induced anemia (P < 0.027). Multiple regression analyses revealed a significant relationship of PIH with TIMP-4 levels, BMI, and family history (combined area under the receiver operating characteristic curve = 0.820).

CONCLUSION

Upregulation of plasma TIMP-4 might contribute to PIH processes. Potential risk factors of this disease may include a family history of PIH and BMI. The combination of TIMP-4 levels and these risk factors may have some predictive values for PIH. Future multicenter studies including greater numbers of samples, analyzed proteins, and risk factors are needed to obtain a higher predictive value of the model for the clinical diagnosis of PIH.

Placental vascular indices (VI, FI and VFI) in intrauterine growth retardation (IUGR). A pooled analysis of the literature

OBJECTIVE

I performed a systematic review and pooled analysis to study the utility of the placental vascular flow indices vascularization index (VI), flow index (FI) and vascularization flow index (VFI) in the prediction or identification of in-utero growth restriction (IUGR).

METHOD

A comprehensive literature search for relevant studies was conducted using PubMed and Web of Knowledge databases. Included were cohort or case-control studies which reported (1) the statistical position and dispersion of vascular indices in a population of normal pregnancies at various trimesters of pregnancy; (2) correlation between vascular indices and gestational age; or (3) the vascular index values stratified according to the presence of SGA/IUGR versus a population of controls.

RESULTS

Seven studies met the criteria of inclusion, for a total of 788 controls and 82 SGA cases in the first trimester, and 169 controls and 80 IUGR cases essentially enrolled in the 3rd trimester. After normalization of the means, the pooled detection rates (DRs) at a 10% false positive rate were 32.5%, 53.8% and 51.0%, respectively, for the vascular indices VI, FI and VFI in the third trimester. No significant discriminant ability was detected in the first trimester.

CONCLUSION

A significant DR for IUGR was demonstrated only in the third trimester, thus limiting the utility of vascular indices to predict IUGR. VI and VFI are more reliable and yield better DR and better performance in terms of homogeneity than FI and should be evaluated in the management of third trimester IUGR and prediction of outcome.

Placental vascularization alterations in hypertensive disorders complicating pregnancy (HDCP) and small for gestational age with HDCP using three-dimensional power doppler in a prospective case control study

Background

Hypertensive disorders complicating pregnancy (HDCP) continues to be a leading cause of maternal and neonatal mortality and morbidity. The clinical value of placental three-dimensional power Doppler (3DPD) in assessing HDCP requires further confirmation. The research was developed to assess changes of placental vascularity in HDCP using 3DPD and to investigate the placental vascularity in small for gestational age (SGA) compared with not-SGA in patients with HDCP.

Methods

There were 126 normotensive and 128 hypertensive pregnant women included in this prospective case–control study from March 2011 to March 2013. Pregnant women underwent 3DPD. Vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were obtained. The placental 3DPD indices, umbilical artery systolic and diastolic ratio (S/D) and pregnancy outcomes were compared between the groups.

Results

The placental VI and VFI were significantly lower in hypertensive women compared with normotensive women (P < 0.001 and P = 0.014, respectively), and these parameters were significantly reduced in severe preeclampsia (P < 0.001 and P = 0.003, respectively). A weak correlation was found between VI and umbilical artery S/D in HDCP group (r = -0.277, P = 0.001). In HDCP population, neonates who were postnatally diagnosed with SGA had lower VI (P = 0.041) and higher S/D (P < 0.001).

Discussion

The placental vascularity indices decreased in hypertensive women and the reduction inplacental perfusion was consistent with the severity of the hypertensive disorder. The associations betweenplacental vascularization and umbilical artery impedance may be valuable for further researches and arerequired confirmation. The significant differences in the 3DPD placental vascularization between SGA andnot-SGA in hypertensive pregnancy population may show some clinical importance that we could use tobetter assess or predict the progression and adverse outcomes in the future. Although 3DPD quantificationhas been widely used in multiple publications, we have to acknowledge its limitations.

Conclusions

The intraplacental vascularization was poor in HDCP, and especially in severe preeclampsia. Neonates with SGA had poor placental vascularization and higher umbilical artery S/D. Further studies should focus on the clinical assessment of placental 3DPD as well as a combination of placental 3DPD and other fetal Doppler indices to better predict the development and outcomes of preeclampsia.