Ductus venosus Doppler and postnatal outcomes in fetuses with absent or reversed end-diastolic flow in the umbilical arteries

Objective: To evaluate the relationship between ductus venosus Doppler findings on the day of delivery and postnatal outcomes in pregnancies with absent or reversed end-diastolic (ARED) flow in the umbilical arteries. Study design: Postnatal outcomes of 103 newborns of pregnancies with a diagnosis of ARED flow on Doppler velocimetry of the umbilical arteries were analyzed retrospectively between January 1997 and December 2004. Single pregnancies and fetuses without malformations were included. The cases were divided into two groups according to the flow during atrial contraction (a-wave) in the ductus venosus on the day of delivery: group A, 20 cases with absent or reversed flow in the ductus venosus and group B, 83 cases with positive flow. The results were analyzed statistically using the chi-square test, Fisher`s exact test and the Mann-Whitney U test with the level of significance set at 5%. Results: All newborns were delivered by cesarean section. Gestational age was similar in the two groups (group A: 30 weeks and group B: 30.9 weeks, P = 0.23). Absent or reversed ductus venosus flow was associated with the following adverse postnatal outcomes: lower birthweight (P < 0.001), lower Apgar scores in the first (P = 0.001) and fifth minute (P = 0.001), a higher frequency of orotracheal intubation (P = 0.001) and pH at birth less than 7.20 (P < 0.001), pulmonary hemorrhage (P = 0.03), thrombocytopenia (P = 0.02), hypoglycemia (P = 0.01), intracranial hemorrhage (P = 0.02), and postnatal death (P = 0.007). Conclusion: The study of ductus venosus flow may provide additional information regarding the best time for interruption of pregnancies with ARED flow in the umbilical arteries characterized by extreme prematurity. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Fetal tricuspid valve Doppler at 11-13 weeks and 6 days: reference values and reproducibility

Objective To determine normal blood flow velocities across the fetal tricuspid valve (TV) at 11-13 weeks and 6 days of gestation and to examine the reproducibility of these measurements. Methods A prospective study involving 166 normal singleton pregnancies examined at 11-13 weeks and 6 days was carried out. Descriptive analysis of E- and A-waves` maximum velocities, E/A ratio, duration of the cardiac cycle (C) and diastole (D) and D/C ratio were calculated. Intraobserver and interobserver agreement analysis was performed in a subgroup of 12 cases. Results Average (+/- SD) flow velocities were: E-wave, 25.0 (+/- 4.6) cm/s; A-wave. 42.9 (+/- 5.9) cm/s; E/A, 0.58 (+/- 0.07); cardiac cycle, 390 (+/- 21.1) ms; diastole, 147 (+/- 18) ms and D/C, 0.38 (+/- 0.04). Significant correlation was observed between all parameters (except A-wave) and gestational age but not with nuchal translucency (NT). Intraclass correlation coefficients (interobserver, intraobsever examiner I and intraobserver examiner 2) were: E-wave, 0.53, 0.53 and 0.64; A-wave, 0.45, 0.46 and 0.49; cardiac cycle, 0.70, 0.79 and 0.84 and diastole, 0.63, 0.85 and 0.82, respectively. Conclusions The present study establishes normal Doppler parameters for blood flow across the TV at 11 - 13 weeks and 6 days and demonstrates that these parameters do not correlate with NT measurement and have good/moderate reproducibility. Copyright (C) 2010 John Wiley & Sons, Ltd.

Ultrasonography in pregnant women with antiphospholipid syndrome using salicylic acid and heparin

The objective of the present study was to evaluate fetal biometry, Doppler values, and perinatal outcomes in pregnant women with antiphospholipid syndrome treated with acetylsalicylic acid and heparin. Twenty-five pregnant women with antiphospholipid syndrome using 100 mg/day acetylsalicylic acid and 5,000 IU heparin every 12 h were evaluated in this prospective observational study. Ultrasonography was performed between 24 and 38 weeks of gestational age to assess estimated fetal weight, placental thickness, amniotic fluid index, fetal biophysical profile and Doppler evaluation of maternal uterine arteries, and fetal middle cerebral and umbilical arteries. Data regarding Apgar score, gender, delivery mode, and birth weight and length were recorded after birth. The observed values for ultrasonographic assessment and perinatal outcomes were not very different from the expected values for normal pregnancies. The birth weight was 2863.3 +/- A 737.7 g (mean +/- A SD) and length was 46.8 +/- A 4.2 cm. Only one newborn (4%) had the 1-min Apgar score < 7 and all had the 5-min Apgar score > 7. Gestational and perinatal evaluation of pregnant women with antiphospholipid syndrome using both acetylsalicylic acid and heparin was reassuring.

Evaluation of ductus venosus and inferior vena cava by using multiple Doppler ultrasound parameters in healthy fetuses

The objective of this study was to describe multiple Doppler ultrasound parameters of ductus venosus and inferior vena cava in fetuses at gestational ages ranging from 22 to 38 weeks. In this prospective observational study, Doppler ultrasound exams were performed in 45 healthy fetuses at 22, 26, 34, and 38 weeks. Maximum venous velocity, minimum venous velocity, venous pulsatility index, and venous acceleration time (VAT) (defined as the time between minimum and maximum venous velocity) were evaluated at those gestational periods. Increase in the velocities and decrease in the pulsatility index were observed in these vessels throughout gestational age. The VAT increased with gestational age. The VAT, a Doppler parameter still not described elsewhere, increased during pregnancy could be related to a longer period of time needed to fill the atrium in bigger hearts. In this study, we provide reference values for VAT in healthy fetuses.

LONGITUDINAL REFERENCE VALUES FOR DUCTUS VENOSUS DOPPLER IN LOW-RISK PREGNANCIES

The aim of this study was to establish normal ranges of blood flow velocities and indices in the fetal ductus venosus (DV) during the second half of normal pregnancy. A Doppler study of 60 healthy pregnant women without fetal pathologies was performed during the second half of pregnancy. The peak systolic velocity (PSV), peak diastolic velocity (PDV), maximum velocity during atrial contraction (VAC), peak systolic velocity/maximum velocity during atrial contraction (S/A ratio), pulsatility index for the vein (PIV), preload index (PLI) and velocity index for the vein (VIV) were calculated from the DV at 4-week intervals. A significant increase in PSV, PDV and VAC was observed from the 20-23(6/7) to the 28-31(6/7) weeks, with stabilization of values until the end of the pregnancy. On the other hand, the study showed a significant decrease for the S/A ratio, PIV, PLI and VIV from the 20-23(6/7) to the 28-31(6/7) weeks and remaining stable from then until term. (E-mail:dralemar@uol.com.br) (C) 2010 World Federation for Ultrasound in Medicine & Biology.

Lack of Circadian Variation of Pulse Wave Velocity Measurements in Healthy Volunteers

Arterial stiffness is an independent marker of cardiovascular events. Pulse wave velocity (PWV) is a validated method to detect arterial stiffness that can be influenced by several factors including age and blood pressure. However, it is not clear whether PWV could be influenced by circadian variations. In the present study, the authors measured blood pressure and carotid-femoral PWV measurements in 15 young healthy volunteers in 4 distinct periods: 8 am, noon, 4 pm, and 8 pm. No significant variations of systolic (P=.92), mean (P=.77), and diastolic (P=.66) blood pressure among 8 am (113 +/- 15, 84 +/- 8, 69 +/- 6 mm Hg), noon (114 +/- 13, 83 +/- 8, 68 +/- 6 mm Hg), 4 pm (114 +/- 13, 85 +/- 8, 70 +/- 7 mm Hg), and 8 pm (113 +/- 7, 83 +/- 10, 68 +/- 7 mm Hg), respectively, were observed. Similarly, carotid-femoral PWV did not change among the periods (8 am: 7.6 +/- 1.4 m/s, noon: 7.4 +/- 1.1 m/s, 4 pm: 7.6 +/- 1.0 m/s, 8 pm, 7.6 +/- 1.3 m/s; P=.85). Considering all measurements, mean blood pressure significantly correlated with PWV (r=.31; P=.016). In young healthy volunteers, there is no significant circadian variation of carotid-femoral PWV. These findings support the concept that it does not appear mandatory to perform PWV measurements at exactly the same period of the day. J Clin Hypertens (Greenwich). 2011;13:19-22. (c) 2010 Wiley Periodicals, Inc.