Mariusz Dubiel

Uterine artery color Doppler assisted veloeimetry and perinatal outcome

Background. Previously, we have found uterine artery blood veloeimetry performed with Doppler ultrasound without vessel visualization to be a poor predictor of perinatal outcome. The aim of this study was to ascertain whether the combination of color Doppler imaging with the method would improve its predictive value.

Middle cerebral artery velocimetry as a predictor of hypoxemia in fetuses with increased resistance to blood flow in the umbilical artery

About half of all fetuses with increased resistance to blood flow, but with still detectable diastolic blood velocity in the umbilical artery (UA), show signs of imminent asphyxia during labour indicating a need for operative delivery. Fetal brain-sparing during hypoxia is characterized by an increase in diastolic and mean blood flow velocity in the middle cerebral artery (MCA). The aim of this study was to assess whether MCA blood velocity in pregnancies with increased resistance to blood flow in the feto-placental circulation could predict the development of fetal asphyxia during labour. Fifty pregnant women with signs of increased feto-placental vascular resistance between 31 and 42 weeks of gestation were studied serially by Doppler ultrasound and the last examination was correlated to perinatal outcome. The MCA pulsatility index (PI), cerebroplacental PI ratio and mean MCA blood velocity were calculated and correlated to fetal outcome. Fetal brain-sparing was defined as MCA PI < mean -2 S.D., cerebroplacental PI ratio < 1.08 and mean MCA blood velocity >mean + 2 S.D. No significant association was found between signs of fetal brain-sparing and the perinatal outcome. Among fetuses with signs of increased resistance to flow in the umbilical artery, velocimetry of the middle cerebral artery did not identify those that would not withstand the strain of labour.

Increased uterine artery vascular impedance is related to adverse outcome of pregnancy but is present in only one-third of late third-trimester pre-eclamptic women.

Signs of increased uterine artery vascular impedance in mid‐gestation are strongly related to pre‐eclampsia later in pregnancy. Whether this is true for the late third trimester is, however, unclear. The aim of the present study was to analyze the frequency of increased uterine artery vascular impedance in the third trimester, and its relationship to abnormal umbilical artery Doppler and adverse outcome of pregnancy.

New score indicating placental vascular resistance.

Background.  Umbilical artery Doppler velocimetry is a routine method for fetal surveillance in high‐risk pregnancy. Uterine artery Doppler seems to give comparable information, but it can be difficult to interpret as there are two arteries, which might show notching and/or increased pulsatility index (PI) as signs of increased vascular impedance. Combining the information on vascular resistance on both sides in a new score might simplify and improve evaluation of placental circulation.

Two types of umbilical venous pulsations and outcome of high-risk pregnancy

Normally, blood flows evenly in the umbilical vein, without fluctuation. A pulsating pattern has been reported during fetal heart failure and asphyxia. Recently we have noticed two types of pulsating pattern; its relationship to adverse outcome is unclear. In a prospective multicenter study, recording of umbilical cord venous blood flow was conducted in high-risk pregnancies admitted for routine artery Doppler. In cases of pulsating flow or signs of vascular resistance in the umbilical artery, the examination was extended to the intra-abdominal part of the umbilical vein. Venous pulsation, single or double, were noted and correlated to perinatal outcome. Venous flow pulsatility was noted in 83 fetuses during 2 years, 26 had a double pulsating pattern, which was closely related to increased vascular resistance in the umbilical artery and perinatal mortality. A single pulsating venous pattern in one location had a good prognosis. In conclusion a double pulsating venous pattern, especially if extending to the cord, is an ominous finding in high-risk pregnancy associated with poor perinatal outcome. A single pulsating pattern predicted a much better outcome and might be an indication for delivery in the high-risk case.

Ductus venosus velocimetry in high-risk pregnancies

OBJECTIVE Umbilical venous (UV) blood velocity pulsations have been considered as a late sign of fetal hypoxemia in high-risk pregnancies. Ductus venosus (DV) functions as a pressure filter as it conducts umbilical blood into the inferior vena cava of the fetus. The aim of this paper was to evaluate whether DV Doppler velocimetry might give earlier indication of fetal hypoxemia than does UV blood velocity. DESIGN Recording of DV blood velocity in complicated pregnancies referred for umbilical artery (UA) velocimetry as one aspect of fetal surveillance. METHOD DV and UV blood velocities were recorded serially by Doppler ultrasound in 87 high-risk pregnancies and the results of the last examination before delivery were correlated to perinatal outcome. RESULTS Abnormal DV blood velocity waveforms recorded in 26 pregnancies were not correlated to perinatal outcome, except for low Apgar score at one minute of life. Abnormal UV blood velocity pulsations in the cord were recorded in 11 fetuses, of which only 6 had abnormal DV velocimetry. UV pulsations were related to adverse perinatal outcome and all these fetuses had abnormal UA velocimetry. CONCLUSION Abnormal DV blood velocity is more frequently recorded in high-risk pregnancies than UV pulsations, but appears to be a poor indicator of adverse perinatal outcome.

Biochemical tissue-specific injury markers of the heart and brain in postpartum cord blood

OBJECTIVE We sought to establish references ranges and to test the hypothesis that biochemical tissue-specific markers for the heart in umbilical cord blood of newborns with cardiac defects and intrauterine growth restriction (IUGR) are abnormal. STUDY DESIGN A prospective study was conducted. Serum samples of the umbilical vein (n = 280) and artery (n = 156) from 599 healthy newborns at 37(+0)-42(+0) weeks of gestation were collected. Total creatine kinase (CK), CK-MB heart type (CK-MB), cardiac troponin T (cTnT), myoglobin, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and S100 were measured. Reference ranges for each marker were constructed. Concentrations of tissue-specific markers from umbilical cord blood of neonates with cardiac defects (n = 10) and IUGR (n = 41) were plotted against the established reference ranges. RESULTS Reference ranges for each studied marker were established for both umbilical artery and vein. In fetuses with cardiac defects, both NT-proBNP (4/6 [66%] in the artery, 7/10 [70%] in the vein) and cTnT (2/10 [20%] in the vein) were increased. In fetuses with IUGR in the vein, NT-proBNP (10/41 [24%]) and cTnT (5/41 [12%]) were increased, whereas S100 (9/41 [21%]) was decreased. CONCLUSION In a subset of neonates with cardiac defects or growth restriction, irrespective of the pH at birth, tissue-specific injury markers for the heart in umbilical cord blood are abnormal.

Abnormal uterine Doppler is related to vasculopathy in pregestational diabetes mellitus

Background— The aim of the study was to evaluate the relation between maternal placental Doppler velocimetry, levels of the maternal glucose, and clinical signs of vasculopathy in pregnancy complicated by pregestational diabetes mellitus. Methods and Results— A retrospective study of 155 pregestational diabetic women between the 22nd and 40th weeks of pregnancy, categorized in White classification as B, 49; C, 40; D, 22; R, 20; F, 5; and RIF, 19. Cases in classes R, F, and R/F were defined as having vasculopathy. Doppler velocimetry of umbilical and uterine arteries was evaluated for vascular impedance, both in terms of pulsatility index (PI) for both arteries and a notch in early diastole in the uterine arteries. The last examination before delivery was used for analysis. Increased umbilical artery PI was seen in 19 and a uterine artery abnormality in 45 cases. There was a correlation between levels of HbAlc and increased vascular impedance in the uterine and umbilical arteries. Signs of increased uterine artery vascular impedances were significantly related to pregestational vasculopathy. In cases of small-for-gestational-age newborn infants, PI was significantly increased in uterine and umbilical arteries. Furthermore, PI in macrosomic fetuses was significantly lower than in normal infants. Abnormal uterine artery Doppler was also strongly related to adverse outcome. Conclusions— Abnormal uterine artery Doppler is related to pregestational vasculopathy and adverse outcome of pregnancy. The results suggest that the uterine arteries are affected in women with clinical signs of pregestational vasculopathy. This may influence placental perfusion and fetal well-being.

Evaluation of fetal circulation redistribution in pregnancies with absent or reversed diastolic flow in the umbilical artery

AIM To record blood flow velocimetry in the superior mesenteric, hepatic and middle cerebral arteries for detection of circulation redistribution and prediction of perinatal outcome in fetuses with absent or reversed diastolic flow in the umbilical artery. STUDY DESIGN The fetal superior mesenteric, hepatic and middle cerebral artery blood velocimetry was recorded in 33 pregnancies complicated by pregnancy-induced hypertension and/or intra-uterine growth retardation between 27 and 41 weeks of gestation. Uterine artery and umbilical vein velocimetries were also recorded. RESULTS An abnormal mesenteric artery pulsatility index (PI) was found in four cases; two newborns died due to prematurity, growth retardation and necrotizing enterocolitis. An abnormal fetal hepatic artery PI was found in 17 cases. The brain-sparing effect in the middle cerebral artery was found in 16 cases; three newborns died after delivery. Signs of redistribution in mesenteric, hepatic and middle cerebral artery velocimetry were not related to most of the perinatal outcome variables. Umbilical vein velocimetry correlated with low arterial and venous pH. All perinatal mortalities had umbilical venous pulsations. CONCLUSIONS Signs of visceral circulation redistribution could not predict adverse outcome. Umbilical venous pulsations were, however, seen in nearly all fetuses; this was the only variable suggesting adverse outcome in the present study of severely compromised fetuses.

Doppler velocimetry in the evaluation of fetal hypoxia.

Abstract Knowledge of fetal hemodynamic physiology has developed enormously during the last two decades due to Doppler ultrasound. Some of this knowledge has been utilized for routine surveillance of high-risk pregnancies. The prediction of fetal hypoxia before the development of life lasting sequel is of major importance, especially in the very premature case with absent end-diastolic blood flow in the umbilical artery before lung maturity. This review gives an overview of the present knowledge in this field.