Ductus Venosus Blood Flow Velocity Research Articles

The role of individual blood flow parameters through ductus venosus in the first and second trimesters of pregnancy in predicting the condition of the fetus and newborn.

To predict fetal and neonatal outcome during pregnancy based on detailed analysis of ductus venosus blood flow velocities in first and second-trimester fetuses. A retrospective analysis was made in 680 patients with single pregnancies in years 2015 and 2016. The following ductus venosus blood flow velocities in first and second-trimester were analyzed: S-wave velocity, D-wave velocity, a-wave velocity, Tmax velocity, PIV. Results were divided into sub-groups with reduced value, normal value and increased value and compared with fetal and neonatal condition. The relationship between the increased PIV value in the first trimester of pregnancy and an increased risk of chromosomal aberrations was observed, whereas the increased DV PI value in the second trimester of pregnancy with reduced A -wave were associated with a higher incidence of FGR. No correlation between the remaining DV blood flow velocities in the first and second trimester of pregnancy and the more frequent occurrence of fetal and neonatal complications has been confirmed. The increased DV PIV is a good prognostic tool for the detection of chromosomal aberrations in first trimester of pregnancy. In the second trimester, the increased DV PIV and the reduced A- wave velocity correlate with the fetal growth restriction. Ductus venosus seems to be an indirect indicator of intrauterine hypoxia with moderate prognostic value for adverse obstetric outcomes.

Reference ranges for flow velocities and the indices of the ductus venosus in low-risk pregnancies

Objective:Ductus venosus blood flow velocity measurements are mandatory in many clinical indications. The evaluation of the flow is performed either by comparing results with general reference tables or by qualitative assessment of the “a” flow, in regard to reversed or absent flow in the spectral waveforms. The aim was to develop normal reference ranges in low-risk pregnancies in our population.Material and Methods:Measurements of flow velocities (S, v, D, a) and indices (pulsatility index for veins, peak velocity index for veins, a/S, S/a) were performed by a single experienced specialist in 1279 singleton, uncomplicated pregnancies between 11 and 40 weeks gestation. The absolute flow velocities (S, v, D, a, VmPeak) and indices were obtained from spectral waveforms using the equipment producer’s inbuilt system. The still images were stored in the picture archiving and communication system.Results:The predicted reference ranges of the ductus venosus blood flow velocities according to the gestational age are shown in tables and graphics. Predicted reference curves based on the 5th and 95th percentiles according to gestational week were plotted and are given in tables and figures.Conclusion:Normal reference ranges for absolute flow velocities and indices were calculated from a population of uncomplicated pregnancies attending a tertiary care center. The measurements were made from both the classic patterns of the waveforms and also considered variants of the spectral waveforms, which have recently been reported, for the first time in the medical literature.

VP42.03: The role of ductus venosus blood flow velocities in first and second trimester of pregnancy in prediction of the fetal and neonatal condition

VP42.03: The role of ductus venosus blood flow velocities in first and second trimester of pregnancy in prediction of the fetal and neonatal condition

Ductus venosus blood flow velocity waveforms during the early second trimester of pregnancy in a Thai population.

To establish reference ranges for ductus venosus (DV) blood flow velocities and indices during the early second trimester. A cross-sectional DV Doppler study of fetuses at 15-22 weeks of gestation was conducted at Songklanagarind Hospital, Songkhla, Thailand, during 2013-2014. The peak forward velocities were recorded and the DV indices were calculated. Predicted reference ranges based on the 5th and 95th percentiles according to the week of gestation were constructed. Among 371 fetuses, measurement of DV Doppler waveforms in the sagittal plane was achieved in 97.5% of cases. With advancing pregnancy (weeks 15 to 22), the DV velocities during ventricular systole, early diastole, and atrial contraction increased from 47.48 cm/s to 68.22 cm/s, 42.23 cm/s to 60.52 cm/s, and 15.94 cm/s to 34.84 cm/s, respectively. The time-averaged maximum value increased from 37.61 cm/s to 55.42 cm/s. The DV indices-pulsatility index for the vein, peak velocity index for the vein, preload index, and systolic/a-wave ratio-decreased from 0.79 to 0.59, 0.71 to 0.53, 0.63 to 0.47, and 2.72 to 1.90, respectively. The systolic/diastolic ratio remained relatively constant at 1.12. Normal reference ranges for DV flow velocities and indices during the early second trimester were established.

Reproducibility of fetal ductus venosus blood flow velocity waveforms during first stage of labor

Fetal ductus venosus (DV) blood flow velocity waveforms are significantly altered during contractions in first stage of labor. We have evaluated the reproducibility of these waveforms during and between contractions. 90 women between 37th and 41st week of gestation were included in the study. The measurements of the DV were obtained by three different investigators during and between contractions. The pulsatility index for veins (PIV), peak velocity index for veins (PVIV), and fetal heart rate (FHR) were calculated offline. Furthermore, differences in PVIV (PVIVdiff) and PIV (PIVdiff) and a mean of FHR (FHRmean) were calculated. Statistical analysis was used to verify differences in the PIV, PVIV and FHR during and between contractions of each subgroup as well as for the PVIVdiff, PIVdiff and FHRmean between the subgroups. Investigator 1 examined 49 patients (group 1); investigator 2, 17 patients (group 2) and investigator 3, 24 patients (group 3), respectively. In all subgroups, there was a significant difference for the PVIV and PIV during and between contractions, but not for FHR. There was a correlation between gestational age and PVIVdiff, PIVdiff and FHRmean as well as for maternal age and PVIVdiff and PIVdiff. PVIVdiff and PIVdiff showed significant differences in group 1 compared to groups 2 and 3 (p<0.001), but not between groups 2 and 3. Significant differences in the measurements in the three subgroups have been revealed, which may be due to different timing of measurement during the contraction. For future studies further standardization of the measurement protocol should be established.

Ductus venosus Doppler in fetuses with cardiac defects and increased nuchal translucency thickness

To examine the possible role of Doppler ultrasound assessment of ductus venosus blood flow in screening for major cardiac defects in chromosomally normal fetuses with increased nuchal translucency (NT) thickness at 11 + 0 to 13 + 6 weeks' gestation. Ductus venosus blood flow velocity waveforms were obtained immediately before chorionic villus sampling for fetal karyotyping in fetuses with NT thickness of 3.5 mm or more at 11 + 0 to 13 + 6 weeks of gestation. In the chromosomally normal group fetal echocardiography was performed by a specialist pediatric cardiologist at 11 + 0 to 13 + 6 weeks and/or 18-22 weeks' gestation. Major cardiac defects were diagnosed in 16 (8.4%) of the 191 chromosomally normal fetuses. Reversed or absent flow in the ductus venosus during atrial contraction was observed in 11 of the 16 (68.8%) fetuses with cardiac defects and in 40 of the 175 (22.9%) with no cardiac defects. Multivariate analysis demonstrated that the prevalence of an abnormal A-wave in the ductus venosus in fetuses without major cardiac defects increased with fetal NT thickness (odds ratio (OR), 1.463; 95% CI, 1.183-1.809; P < 0.0001) but in those with cardiac defects it did not change significantly with NT thickness (OR, 2.054; 95% CI, 0.573-7.360; P = 0.269). The likelihood ratio for a major cardiac defect when the ductus venosus flow was abnormal decreased with fetal NT thickness from 4.58 at NT 3.5 mm to 2.47 for NT 5.5 mm, and the likelihood ratio when the ductus venosus flow was normal increased from 0.37 at NT 3.5 mm to 0.43 for NT 5.5 mm. In chromosomally normal fetuses with increased NT the finding of an absent or reversed A-wave in the ductus venosus is associated with a three-fold increase in the likelihood of a major cardiac defect, whereas the finding of normal ductal flow is associated with a halving in risk for such defects.

Ductus venosus Doppler velocimetry in the first trimester: a new finding

To establish reference curves for ductus venosus blood flow velocities during the first trimester and compare them with previously published curves. This was a cross-sectional and retrospective study performed between January 1998 and January 2003. The following inclusion criteria were used: singleton pregnancy, velocity measurements taken when the crown-rump length (CRL) was between 34 and 84 mm, absence of fetal anomalies, full-term pregnancy and newborn birth weight appropriate for gestational age. The following variables of the ductus venosus were measured: peak velocity during ventricular systole (S-wave) and diastole (D-wave), nadir during atrial contraction in late diastole (A-wave), time-averaged maximum velocity (TAMXV) and pulsatility index for veins (PIV). A total of 843 fetuses were included. The mean CRL was 62 (range, 34-84) mm. The S-wave, D-wave, TAMXV and PIV were normally distributed, and logarithmic transformation was performed to achieve a normal distribution for the A-wave. S-wave, D-wave and A-wave and TAMXV increased with CRL. PIV increased up to a CRL of 63 mm and decreased thereafter. Regression analysis revealed a significant quadratic relationship between PIV and CRL. S-wave, D-wave, A-wave velocities and TAMXV in the ductus venosus increase with CRL between 34 and 84 mm. The reference range for PIV has a biphasic pattern, with an initial non-significant increase up to a CRL of 63 mm and a fall thereafter.

Longitudinal reference ranges for ductus venosus flow velocities and waveform indices

Serial Doppler measurements of the ductus venosus are used increasingly for monitoring fetuses at risk of hemodynamic compromise, but existing reference ranges are based on cross-sectional studies and thus are less suitable for comparison with serial measurements. We aimed to establish longitudinal reference ranges for ductus venosus flow velocities and waveform indices and to provide the necessary terms for calculating conditional reference ranges for serial measurements. This was a longitudinal study of 160 low-risk pregnancies. Pulsed Doppler ultrasound was used to record ductus venosus blood flow velocities at 4-week intervals from 20-22 weeks of gestation onwards. With a success rate of 93%, 547 measurements (four or five in each fetus) were used to establish reference ranges. The time-averaged maximum velocity was 50 cm/s at 21 weeks of gestation, increased to 60 cm/s at 32 weeks, and remained so until term. Similarly, the peak systolic velocity increased from 59 cm/s at 21 weeks to 71 cm/s at 31 weeks and remained so until term. The end-diastolic velocity showed a continuous increase from 31 cm/s at 21 weeks to 43 cm/s at 40 weeks. The pulsatility index for veins decreased from 0.57 at 21 weeks to 0.44 at 40 weeks. When conditioned by a previous measurement, the reference ranges for the next observation became narrower and commonly shifted compared with those of the entire population. The new longitudinal reference ranges presented here reflect the development of the ductus venosus flow velocities and velocity indices and are thus appropriate for serial measurements, particularly if conditional terms are included.

1095: Prenatal diagnosis during the first trimester

Ultrasound measurement of nuchal translucency thickness is an effective method of screening for chromosomal abnormalities at 11 to 13 + 6 wk of gestation. It was suggested that, when combined with maternal age, this method can identify about 80% of pregnancies with trisomy 21 at a 5% false-positive rate. It was shown that by the combination of this methodology with the determination of maternal serum free-human chorionic gonadotropin (-hCG) and pregnancy-associated plasma protein-A (PAPP-A), the detection rate of trisomy 21 is about 90%, for a false-positive rate of 5%. Additionally, in chromosomally normal fetuses, increased NT is associated with an increased risk of structural abnormalities, mainly cardiac defects, genetic syndromes and adverse pregnancy outcome. It was also reported that there is an association between chromosomal defects and abnormal ductus venosus blood flow-velocity waveforms (DV-FVWs) at 11 to14 wk of gestation in high-risk pregnancies. More than that, an abnormal DV-FVW is also associated with a high probability of an underlying major cardiac defect, and adverse pregnancy outcome. It was also proposed that a high association between absent fetal nasal bone at the 11 to 13 + 6 gestational wk scan and trisomy so that the addition of this marker could result in a major reduction in the need for invasive testing and a substantial increase in sensitivity. During this lecture, we will review the ultrasound technique for obtaining these different markers correctly according to the Fetal Medicine Foundation criteria. Additionally, we will discuss our experience in two private centers in Argentina during the last 4y. Ultrasound measurement of nuchal translucency thickness is an effective method of screening for chromosomal abnormalities at 11 to 13 + 6 wk of gestation. It was suggested that, when combined with maternal age, this method can identify about 80% of pregnancies with trisomy 21 at a 5% false-positive rate. It was shown that by the combination of this methodology with the determination of maternal serum free-human chorionic gonadotropin (-hCG) and pregnancy-associated plasma protein-A (PAPP-A), the detection rate of trisomy 21 is about 90%, for a false-positive rate of 5%. Additionally, in chromosomally normal fetuses, increased NT is associated with an increased risk of structural abnormalities, mainly cardiac defects, genetic syndromes and adverse pregnancy outcome. It was also reported that there is an association between chromosomal defects and abnormal ductus venosus blood flow-velocity waveforms (DV-FVWs) at 11 to14 wk of gestation in high-risk pregnancies. More than that, an abnormal DV-FVW is also associated with a high probability of an underlying major cardiac defect, and adverse pregnancy outcome. It was also proposed that a high association between absent fetal nasal bone at the 11 to 13 + 6 gestational wk scan and trisomy so that the addition of this marker could result in a major reduction in the need for invasive testing and a substantial increase in sensitivity. During this lecture, we will review the ultrasound technique for obtaining these different markers correctly according to the Fetal Medicine Foundation criteria. Additionally, we will discuss our experience in two private centers in Argentina during the last 4y.

Ductus venosus blood flow velocity characteristics of fetuses with single umbilical artery.

Sonographic Doppler evaluation of the fetal ductus venosus has been proved to be useful in the evaluation of fetal cardiac function. The aim of this study was to investigate the ductus venosus blood flow profile in fetuses with single umbilical artery and to correlate it with the umbilical cord morphology. Fetuses at >20 weeks' gestation with single umbilical artery who were otherwise healthy were consecutively enrolled into the study. The sonographic examination included evaluation of the following Doppler parameters: umbilical artery resistance index, maximum blood flow velocity of the ductus venosus during ventricular systole (S-peak) and atrial contraction (A-wave), ductus venosus time-averaged maximum velocity (TAMXV), and pulsatility index for veins (PIV). The cross-sectional area of the umbilical cord and its vessels were measured in all cases. The Doppler and morphometric values obtained were plotted on reference ranges. A total of 88 fetuses with single umbilical artery were scanned during the study period. Of these 52 met the inclusion criteria. The S-peak velocity, A-wave velocity, and TAMXV were below the 5th centile for gestational age in 57.7%, 59.6%, and 57.7% of cases, respectively. The PIV was within the normal range in 80.1% of cases. The umbilical vein cross-sectional area of fetuses with single umbilical artery was above the 95th centile for gestational age in 34.6% cases. The ductus venosus blood flow pattern is different in fetuses with single umbilical artery from that in those with a three-vessel cord. This difference may be caused in part by the particular morphology of umbilical cords with a single artery.

Arterial and Ductus venosus Doppler in Fetuses with Absent or Reverse End-Diastolic Flow in the Umbilical Artery: Longitudinal Analysis

Objective: To evaluate alterations of arterial and ductus venosus blood flow velocities during deterioration and their interdependence. Methods: 37 high-risk pregnancies complicated by umbilical absent or reverse end-diastolic flow velocities (AREDV) were monitored by measurement of the pulsatility index of the umbilical artery, middle cerebral artery and ductus venosus waveforms. Results: The mean observation period was 16.5 days. There was a significant change in the pulsatility of waveforms in all vessels over the observation period. Compared with the ductus venosus, pulsatility of waveforms in the middle cerebral artery diverged from the normal range 2.2 weeks earlier. Increase in pulsatility in the umbilical artery was concomitant with venous but not with cerebral flow alterations. In addition, there was a correlation between the increase of venous but not arterial pulsatility and perinatal acidemia. Variability of pulsatility index values of the umbilical artery and the ductus venosus but not of the middle cerebral artery increased towards delivery. Conclusions: Ductus venosus Doppler allows detection of further deterioration in centralized fetuses with umbilical AREDV. However, striking short-term variability has to be taken into account when considering this parameter.

Normal values of fetal ductus venosus blood flow waveforms during the first stage of labor.

To present normal values of fetal ductus venosus blood flow waveforms during the first stage of labor during and between contractions. Seventy-eight women between the 37th and 41st weeks of gestation were included in the study. At distinct stages of cervical dilation, blood flow velocity waveforms of the fetal ductus venosus during and between contractions were visualized in fetuses with a normal non-stress test. The pulsatility index for veins, peak velocity index for veins and fetal heart rate were calculated off-line. The means +/- standard deviations (SD) during and between contractions were compared using the Wilcoxon test. Ductus venosus blood flow velocity waveforms were visualized during 331 contractions and 375 episodes of uterine quiescence in 74 of 78 fetuses (95%) during normal labor. The mean +/- standard deviation values of pulsatility and peak velocity indices for veins during contractions were 1.66 +/- 0.85 (median: 1.56, range: 0.29-4.69) and 1.46 +/- 0.65 (median: 1.34, range: 0.26-3.13), respectively. Between contractions the values were 0.48 +/- 0.19 (median: 0.46, range: 0.14-1.00) for the pulsatility index and 0.44 +/- 0.18 (median: 0.42, range: 0.14-1.00) for the peak velocity index for veins. These differences during and between contractions were highly significant (P-value < 0.0001), whereas the fetal heart rate showed no significant differences. There are significant differences in fetal ductus venosus blood flow waveforms during and between labor contractions. Further studies should evaluate whether these normal values of the fetal ductus venosus are beneficial for risk evaluation in fetuses with an abnormal non-stress test and/or intrauterine growth restriction.

F61The ductus venosus blood flow velocity waveforms during labour in 42 singleton fetuses at term

BackgroundThe aim of this study was to learn about the physiological changes in the ductus venosus blood flow velocity waveforms during labour.MethodDuctus venosus flow curves were obtained by Doppler ultrasonography during and in‐between uterine contraction during the first and second stage of labour in 42 singleton fetuses at term. In every patient we tried to measure at four different times of dilatation of the cervix (0–2 cm, 2–4 cm, 6–8 cm, fully dilated). In average we obtained 3.76 measurement periods. At every period the ductus was continuously recorded on video tape throughout 5–10 min.ResultsChanges in the ductus venosus blood flow were observed during labour. The flow profiles did not change with increasing cervix dilatation, but they changed during contraction compared to in absence of contractions. The peak velocity index (PVIV) and the pulsatility index for veins (PIV) within uterine contraction differed significantly (P &lt; 0.001) compared to pviv and piv in absence of contractions in all four stages of cervix dilatation.ConclusionsThe ductus venosus blood flow velocity waveforms undergo great changes intrapartum in cases of uneventful pregnancy and delivery. It has to be further evaluated which subgroup of pregnancies will benefit from Doppler velocimetry of the ductus venosus for intrapartum surveillance.