To examine the value of the fetal biophysical profile (FBP) and the Doppler cerebro-umbilical ratio (C/U) in the assessment of perinatal outcome in growth-restricted and hypoxic fetuses.
The ...prospective clinical study included 87 pregnant women with singleton pregnancies at 28-42 weeks of gestation with clinically verified intrauterine growth restriction (IUGR). After assessment of FBP, flow velocity waveforms from the umbilical and middle cerebral arteries were recorded and the C/U ratio was calculated. The C/U ratio and FBP were assessed twice a week. At delivery, umbilical arterial pH, the occurrence of meconium-stained amniotic fluid (MAF), Apgar score at 5 min and the incidence of cesarean sections were used as outcome parameters.
The mean FBP value was 5.5 +/- 0.96 in cases with MAF, and 6.88 +/- 0.26 in cases without MAF. Also, there was no statistical significance in the relation between the C/U ratio and the appearance of MAF. At pH >7.2, the mean FBP value was 7.11 +/- 0.23, while it was 2.83 +/- 0.79 in newborns with acidosis. Both FBP and C/U values were statistically correlated with pH (p < 0.01). The mean umbilical arterial pH was 7.31 +/- 0.0 at a C/U ratio of >/=1 and 7.21 +/- 0.03 at a C/U ratio of <1. In cases with Apgar scores of 8-10, the mean FBP value was 7.28 +/- 0.23, at Apgar scores of 5-7 it was 3.9 +/- 0.52, while at Apgar scores of 0-4 the mean FBP value was 1.5 +/- 0.5. The mean Apgar score at 5 min was 9.54 +/- 0.09 at a C/U ratio of >/=1, and 8.12 +/- 0.49 at a C/U ratio of <1. The mean FBP value in cases of vaginal delivery was 7.55 +/- 0.31. In cesarean section deliveries, the mean FBP value was 5.97 +/- 0.37. Also, there was a high frequency of cesarean sections in growth-restricted fetuses with a C/U ratio of <1 (p < 0.05), i.e. slightly less than FBP.
FBP and C/U ratio were associated with low arterial pH, low Apgar score and the rate of cesarean sections (p < 0.05), but there was no association between FBP or C/U ratio and the appearance of MAF (p > 0.5). Due to their good predictive value the FBP and C/U ratio could be used in the prenatal monitoring of growth-retarded and hypoxic fetuses. These two methods can be used as important parameters in the decision to end pregnancies with IUGR, when pathological values occur. Thus a reduction in perinatal morbidity, mortality and the incidence of infants with poor neurologic outcome can be expected.
OBJECTIVETo assess uterine and fetal blood flows by Doppler velocimetry and fetal growth and oxygenation in pregnant ewes treated daily with cocaine and to determine whether cocaine impairs fetal ...cardiac and cerebral reactivity.
METHODSThe study groups received 70 mg (n = 7) or 140 mg (n = 7) of cocaine and the control group (n = 7) received placebo injected intramuscularly daily on days 60–134. Hemodynamic data were measured at rest and during two acute hypoxic tests at cesarean delivery performed on day 134.
RESULTSThe fetal heart rate (FHR) and umbilical and uterine resistance indices (RIs) were higher in the cocaine groups than in the control group (FHR187 ± 8 and 166 ± 8 beats per minute at 83 and 123 days, respectively, in controls and 9–11% higher in cocaine groups; umbilical RI0.79 ± 0.06, 0.60 ± 0.04, and 0.52 ± 0.06, at 83, 105, and 123 days, respectively, in controls and 11–17% higher in the cocaine groups P <.01; and uterine RI0.40 ± 0.05, 0.40 ± 0.04, and 0.37 ± 0.04, at 83, 105, and 123 days, respectively, in controls and 13–35% higher in cocaine groups P <.05). At delivery on day 134, the following characteristics were found to be different in the cocaine groupsfetal weight (4.03 ± 0.2 kg in controls and 15–21% lower in the cocaine groups P <.02), partial pressure of oxygen (26.5 ± 1.4 mmHg in controls and 15–16% lower in cocaine groups P <.05), umbilical RI (0.40 ± 0.03 in controls and 11–17% higher in cocaine groups P <.01), cerebral RI (0.61 ± 0.03 in controls and 9–15% lower in cocaine groups P <.01), and cerebral-umbilical ratio (1.52 ± 0.04 in controls and 22–23% lower in cocaine groups P <.001). During the hypoxic tests, the cerebral RI (P <.05) and the cerebral-umbilical ratio (P <.05) decreased significantly less in the two cocaine groups. The FHR response was reduced significantly less in the two cocaine groups (P <.05).
CONCLUSIONLong-term exposure to cocaine induces uterine and fetal blood flow disorders, fetal growth restriction, and hypoxia. It reduces the capability of the cerebral vessels to vasodilate and the heart rate to increase during acute hypoxia.
Objective
To estimate the value of a new vascular score, hypoxia index (HI), in prediction of functional and/or structural brain lesions caused by fetal hypoxia and to examine the relationship ...between this index, Doppler cerebral‐umbilical ratio (C/U) and neonatal neurosonography in growth retarded and hypoxia fetuses.
Study design
In the prospective study 41 growth retarded fetuses were included from 29 to 40 weeks of gestation. Flow velocity waveforms the umbilical and middle cerebral arteries were recorded each other day, at least two weeks. The C/U ratio and HI were calculated. After the birth, obstetric parameters and ultrasound of neonatal brain were used as outcome parameters.
Results
Doppler C/U ratio < 1 as well as HI > 150 were associated with poor perinatal outcome. The neonatal brain damage was detected in 16 growth‐retarded and hypoxic fetuses. Hypoxia index had greater statistic significance in the prediction of neonatal brain lesions. Also, specificity and sensitivity of HI was better than the last value of C/U ratio measured before delivery.
Conclusions
The C/U ratio and HI represent the best indicators for early detecting and assessment of fetal hypoxia. Furthermore, they may also be parameters for the prediction of poor neurological outcome in pregnancies with growth retardation. So, the use of HI would represent a significant advance in prevention of hypoxic brain lesions, which are one of the most frequent causes of perinatal morbidity and mortality.
Objective
To study the cerebral and umbilical hemodynamics changes in hypoxic and growth‐retarded fetuses. To determine if at long‐term, fetal brain hyperperfusion with loss of cerebral vascular flow ...velocity variability is associated with brain damage and poor fetal outcome.
Methods
The fetal blood flow redistribution was assessed by using Doppler cerebral‐umbilical ratio in 8 growth‐retarded fetuses, mainly every day. The evolution of the fetal hemodynamics was interpreted according to the clinical, anatomical and histological data.
Results
All 8 fetuses had poor fetal outcome including fetal death (n = 5). Fetal blood flow redistribution with brain hyperperfusion was detected in all fetuses during the whole period of observation. The early phase of fetal deterioration was characterized by the development of oligohydramnios and the disappearance of the cerebral flow velocity variability. During the later phase of deterioration, fetal heart rate decelerations and the increase of cerebral vascular resistance with reduction of brain perfusion were detected. Histological study of the brains showed hypoxic lesions.
Conclusion
The loss of variability of the cerebral resistance index, in the cases of absent umbilical end diastolic flow, and the loss of variability of the cerebral‐umbilical ratio in the other cases, identifies the beginning of the period of very high risk for the fetus. Such a pattern may be considered as a predictor of brain lesion and poor fetal outcome. These results also indicate the existence of two phases in the fetal cerebrovascular response to chronic hypoxia.
The aim of the study is the evaluation of variables of the biophysical profile in the assessment of perinatal outcome. The prospective study included 87 pregnant women with singleton pregnancy in the ...28th to 42nd week of gestation with clinically and ultrasonically verified fetal growth retardation, where the fetal biophysical profile was assessed antenatally. Through the factor analysis of biophysical profile variables we obtained values indicating the contribution of individual variables to the predictability of perinatal outcome. 70% of the patients were examined in 15 minutes according to the principles of modified biophysical profile. The most sensitive variable of the biophysical profile in the prediction of perinatal outcome was the amniotic fluid volume, followed by fetal breathing movements, non-stress test and fetal movements, while the lowest prediction value was assigned to the fetal tone. The modified biophysical profiles need to be perfected on a larger number of pregnant women, which would advance the predictability of this method in detection of hypoxically endangered fetuses.
Introduction of transvaginal color Doppler has enabled precise analysis of placental circulation in early pregnancy. The purpose of this paper is to summarize the current understanding of the anatomy ...and physiology of the early placental circulation. Study of uteroplacental circulation has demonstrated a progressive decrease of peripheral resistance from large toward small branches during first and early second trimester of pregnancy. Doppler study of umbilical circulation has also shown a significant fall of resistance from umbilical artery to its branches. Analysis of uteroplacental circulation in abnormal early pregnancy has shown differences in comparison with normal values. Using of transvaginal color Doppler in early pregnancy is not successful in prediction of abnormal late pregnancy. Color Doppler is useful in diagnosis of placental and umbilical cord pathology. The duration of pulsed Doppler examination in early pregnancy should be reduced to minimum if we want to avoid excessive heating of embryonic tissue.
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