Middle cerebral artery velocimetry as a predictor of hypoxemia in fetuses with increased resistance to blood flow in the umbilical artery (original) (raw)
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Al-Azhar Medical Journal, 2016
Background: Although the increased fetal morbidity and mortality associated with post-term pregnancy has long been appreciated, most authors have studied gestational age as the alone contributing factor. The influence of other factors such as maternal age, parity, maternal smoking, fetal genders, birth weight and past history of post-term has not been adequately evaluated, Additionally, the accuracy of earlier studies is limited by the fact that they predate the widespread use of both ultrasonography for accurate gestational dating and intensive fetal testing to establish fetal wellbeing. Objective: the present study was conducted to evaluate the effects of prolonged exceeding 287 days of menstrual age on the Doppler flow velocity waveforms in the umbilical, middle cerebral and uterine arteries, and its impact on neonatal outcome to determine the best predictor of adverse outcome in post-term. Patients and Methods: The present study included 50 pregnant ladies All patients were submitted to ultrasound for detection of fetal genders, fetal weight and amniotic fluid index (AFI) Also, they were submitted to color Doppler velocimetery of fetoplacental and fetal vessels including middle cerebral pulsitility index MCA PI), umbilical artery pulsitility index UA PI), middle cerebral resistance index MCA RI), umbilical artery resistance index UA RI), uterine artery pulsitility index UtA PI),and uterine artery pulsitility index UtA RI). Results: In the present study, there was no statistical signification with gestational age, fetal heart rate and parity. The primary gravida had the highest incidence. There was higher rate of CS which was significant with prolongation of pregnancy, but with no statistically significant difference between adverse and normal outcome Also, the incidence of males was more than females in our population with no significant relation between fetal gender and neonatal outcome. Adverse outcome was associated with lower MCA PI, MCA RI, AFI, Apgar score, and higher UA RI compared to normal outcome with statistically significant difference between them, but there was no statistically significant difference as regard UA PI, UtA PI, UtA RI. Conclusion: The perinatal morbidity and mortality may be increase in post-term pregnancies. However, the all screening tests and Doppler indices may be normal due to mode of delivery, time of delivery, and type of anesthesia during labor. So, during labor, rapid interference should be taken to decrease incidence of adverse neonatal outcome. In post-term pregnancies with adverse outcomes, impedance to flow in umbilical arteries may be increased, while impedance to flow in the fetal middle cerebral arteries may be decreased, but impedance to flow in uterine arteries may be normal
The Scientific World Journal, 2016
Objective. To elaborate curves of longitudinal reference intervals of pulsatility index (PI) and systolic velocity (SV) for uterine (UtA), umbilical (UA), and middle cerebral arteries (MCA), in low risk pregnancies. Methods. Doppler velocimetric measurements of PI and SV from 63 low risk pregnant women between 16 and 41 weeks of gestational age. Means (±SD) for intervals of gestational age and percentiles 5, 50, and 95 were calculated for each parameter. The Intraclass Correlation Coefficients (ICC) were also estimated for assessing intra- and intervariability of measurements. Results. Mean PI of UtA showed decreasing values during pregnancy, but no regular pattern was identified for mean SV. For UA, PI decreased and SV increased along gestation. MCA presented PI increasing values until 32–35 weeks. SV showed higher levels with increasing gestation. High ICC values indicated good reproducibility. Conclusions. Reference intervals for the assessment of SV and PI of UtA, UA, and MCA we...
Early Human Development, 2003
Background: An impaired placental circulation is involved in the mechanism of late fetal heart rate (FHR) decelerations. Objectives: To explore umbilical artery (UA) Doppler velocimetry changes in response to uterine contractions during the oxytocin challenge test (OCT) and assess the potentially clinical value of 'OCT Doppler velocimetry'. Methods: 111 women with pregnancy complications were subjected to an OCT with simultaneous recordings of FHR and UA pulsatility index (PI). Positive OCT cases (late FHR decelarations) were compared with negative OCT cases (normal FHR patterns). Only negative OCT cases were allowed a trial of vaginal delivery. Results: The UA PI was higher in OCT positive (N = 21) than in negative cases (N = 90) during uterine contractions and relaxations ( P < 0.05), but not during basal measurements. A positive OCT, but not negative, was associated with an increase of PI during contractions and relaxations compared with basal measurements ( P < 0.05). Fetal growth restriction (N = 58), operative delivery for fetal distress (ODFD) in labor (N = 10), and birth asphyxia (N = 8) were not associated with PI changes significantly different from cases without these complications. Conclusions: During uterine contractions and relaxations, but not during basal measurements, a significantly higher UA PI evolved in OCT positive cases compared with OCT negative cases. This indicates a pathophysiological mechanism disclosed only during uterine activity. Although these changes would not have been revealed by traditional Doppler velocimetry, the data suggest a limited predictive value of 'OCT Doppler velocimetry' on the short-term neonatal outcome. D
Correlation of fetal middle cerebral artery Doppler indices in IUGR pregnancies
International Journal of Biomedical Research, 2014
Doppler velocimetry studies of placental and fetal circulation can provide important information regarding fetal well being providing an opportunity to improve fetal outcome. The present study was undertaken to evaluate the role of fetal middle cerebral artery blood velocity waveforms, Systolic/Diastolic ratio (S/D), Pulsatility Index (PI), Resistance Index (RI) as predictor of perinatal o utcome in intrauterine growth restriction (IUGR) pregnancies in II nd and III rd trimester. Methods: In the study group, 50 cases of IUGR were studied in II nd and III rd trimester. They were first subjected to ultrasonography biometry and then middle cerebral artery Doppler sonography. Results: In both control and study group the values of S/D ratio, PI and RI in middle cerebral artery decline during II nd to III rd trimester. The values were lower in the study group as compared to the control group. Thus the present study predicts that; a) Lower PI values were suggestive of fetal hypoxia. b) The lower values are due to vasodilatation due to hypoxia in order to supply more blood to the brain to protect it from the damaging effects of hypoxia. Thus the brain is spared from damage. Interpretation and conclusion: Doppler can be considered as one of the important non invasive technique to assess the fetomaternal and uteroplacental circulations. The middle cerebral artery indices were valuable for predicting the outcome of IUGR pregnancies.
Umbilical artery Doppler velocimetry in the prediction of intrapartum fetal compromise
South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 1992
The value of early intrapartum umbilical artery Doppler velocimetry in the prediction of fetal compromise was studied. One hundred patients were recruited into the study and fetal compromise was diagnosed by abnormal first- or second-stage fetal heart rate traces, a 5-minute Apgar score less than 7, or the development of hypoxic ischaemic encephalopathy. Fetal compromise developed in 30 patients. An umbilical artery resistance index (RI) of 0.66 or less did not predict fetal compromise (sensitivity 13%, specificity 89%, positive predictive value 25%, negative predictive value 70%). Since the mean umbilical artery RI was identical in the compromised and the non-compromised groups, we conclude that early intrapartum Doppler velocimetry is of very little clinical value in predicting fetal compromise at term.
Doppler Velocimetry of Umbilical Artery in Normal and Growth Restricted Pregnancy
Bangladesh Journal of Obstetrics & Gynaecology, 2022
Objectives: To evaluate the umbilical arterial blood flow velocity and its various indices during 3rd trimester of pregnancy and to compare these indices in normal and growth restricted pregnancies. Methods: In this study, 50 women with normal singleton pregnancy and 50 women with intrauterine growth restricted (IUGR) pregnancy with expected birth weight <10th percentile of the normal for the gestational age were studied by Doppler evaluation of their umbilical artery, Pulsality Index (PI), Resistance Index (RI) and S/D ratio of the control group and IUGR group were calculated and reference range constructed. Values of Doppler indices of IUGR group were compared with those of the control group. Perinatal outcome was evaluated in relation to the indices. Results: Doppler velocimetry of umbilical artery showed elevated indices in 33 out of 50 cases of IUGR group showing its high sensitivity in diagnosing haemodynamically compromised growth restricted fetuses. Absent end diastolic v...
Fetal adrenal and middle cerebral artery Doppler velocimetry in high-risk pregnancy
Ultrasound in Obstetrics and Gynecology, 2000
Objectives Animal studies have shown that hypoxic fetuses redistribute their blood flow, giving preferential supply to the brain, heart and adrenal glands. The aim of this study was to establish whether blood velocity waveforms in the human fetal adrenal artery and middle cerebral artery showed signs of redistribution of fetal circulation in high-risk pregnancy, and to analyze the relationship between signs of such redistribution and the outcome of pregnancy.