1.
Cheema, Riffat, et al.
(författare)
Signs of fetal brain sparing are not related to umbilical cord blood gases at birth.
2009
Ingår i: Early Human Development. - : Elsevier BV. - 1872-6232 .- 0378-3782. ; 85, s. 467-470
Tidskriftsartikel (refereegranskat) abstract
BACKGROUND: Fetal chronic hypoxia leads to centralization of circulation in order to spare the vital organs brain, adrenals and the heart. This can be documented by Doppler ultrasound. Increased blood velocity in the fetal middle cerebral artery (MCA) is an acknowledged sign of centralization of circulation in chronic hypoxia, and is called brain sparing. AIM: Our aim was to assess the relationship between signs of brain sparing in the MCA and umbilical cord blood gases at birth. STUDY DESIGN: A prospective study. SUBJECTS: Singleton 57 high-risk pregnancies (outcome was compared with 21 normal pregnancies). METHODS: MCA Doppler was performed within 24 h of elective caesarean section in high-risk pregnancies. Umbilical cord blood gases were analysed at birth. MAIN OUTCOME MEASURES: Cord blood gases were related to signs of centralization of fetal circulation in the MCA. RESULTS: No correlation between signs of brain sparing in the MCA and cord blood gases. Apgar score at 5'<7 was seen in three newborns, but only one of these had antenatal signs of brain sparing. Newborns with antenatal brain sparing were admitted more often (p<0.04) and had a longer duration of stay in NICU (p<0.03) compared to newborns without brain sparing. CONCLUSION: Decreased pulsatility index in MCA is an acknowledged sign of fetal centralization of circulation during chronic hypoxia. However, signs of brain sparing are not related to cord blood gases at birth, which might suggest that redistribution of fetal circulation can maintain normal blood gases for a long time during chronic hypoxia.
2.
Gudmundsson, Saemundur, et al.
(författare)
Placental morphologic and functional imaging in high-risk pregnancies.
2009
Ingår i: Seminars in Perinatology. - : Elsevier BV. - 1558-075X .- 0146-0005. ; 33:4, s. 270-280
Tidskriftsartikel (refereegranskat) abstract
The placenta is vital for fetal growth and development. Improvement in ultrasound and magnetic resonance imaging have improved our understanding of placental morphology that can be important as in the case of placental accrete/percreta. Functional imaging is presently mainly performed by the use of Doppler ultrasound and can give information on placental perfusion, which can be vital for clinical diagnosis. This review summarizes the present knowledge on placental imaging and it's clinical value in high-risk pregnancies.
3.
Li, Hui, et al.
(författare)
Acute centralization of blood flow in compromised human fetuses evoked by uterine contractions.
2006
Ingår i: Early Human Development. - : Elsevier BV. - 1872-6232 .- 0378-3782. ; 82:11, s. 747-752
Tidskriftsartikel (refereegranskat) abstract
Background: During fetal hypoxia blood is redistributed to the brain ('brain-sparing'). Sequential changes of the cerebral and placental circulation in parallel in comparisons between basal conditions and acute hypoxic stress have not yet been thoroughly studied in human fetuses. Aim: To explore acute fetal middle cerebral artery (MCA) circulatory changes relative to umbilical artery (UA) blood flow in a clinical experimental model with hypoxic stress provoked by uterine contractions during an oxytocin challenge test (OCT). Study design: Prospective comparative between imminently compromised (OCT positive) and un-compromised (OCT negative) fetuses. Subjects and methods: 82 term pregnancies suspected of intrauterine growth restriction were exposed to simultaneous electronic fetal heart rate monitoring and Doppler recordings of pulsatility index (PI) in the UA and MCA during basal conditions and during uterine contractions and relaxations at an OCT. Outcome measures: Sequential changes of UA and MCA PI, OCT positive vs. negative cases. Nonparametric statistics with a P < 0.05 considered significant. Results: The UA PI was significantly higher in OCT positive cases (N=10) compared with OCT negative cases (N=72) during uterine contractions and relaxations, but not during basal measurements. During contractions and relaxations the MCA PI decreased significantly in both groups (brain-sparing), but significantly more in OCT positive cases. Conclusions: During acute hypoxic stress, changes towards a centralization of blood flow to the brain develop in imminently compromised (OCT positive) fetuses at an expense of the umbilicoplacental. blood flow, and the brain-sparing flow is more pronounced than in uncompromised (OCT negative) fetuses.
4.
5.
Lindqvist, Pelle, et al.
(författare)
Maternal carriership of factor V Leiden associated with pathological uterine artery doppler measurements during pregnancy
2001
Ingår i: BJOG: An International Journal of Obstetrics & Gynaecology. - 1471-0528. ; 108:10, s. 5-1103
Tidskriftsartikel (refereegranskat) abstract
Abstract To determine whether increased vascular resistance in the uterine artery is associated with carriership of factor V Leiden, a retrospective study was undertaken of 231 pregnant women who were monitored with Doppler velocimetry of the uterine arteries. These women had been part of a prospective study of 2,480 pregnant women in whom factor V Leiden had been analysed. When compared with non-carriers of factor V Leiden, carriers had a tendency towards an increased proportion of pathological Doppler measurements, including a significant increase in bilateral uterine artery notches (7/33 vs 16/198, relative risk 3.1; 95% CI 1.2-8.1). This suggests an increased vascular resistance in the uteroplacental circulation among carriers of factor V Leiden.
6.
Breborowicz, Andrzej, et al.
(författare)
Fetal pulmonary and cerebral artery Doppler velocimetry in normal and high risk pregnancy
2014
Ingår i: Ginekologia Polska. - 0017-0011. ; 85:1, s. 26-30
Tidskriftsartikel (refereegranskat) abstract
Studies on fetal lung/brain circulation by means of power Doppler technique have suggested a marked reduction in lung perfusion in high-risk pregnancies as a sign of circulation redistribution. The ratio between lung/brain perfusion might therefore give a new method to predict fetal circulation centralization. Objective: The aim of the present study was to obtain fetal lung and cerebral artery ratio in normal and high-risk pregnancies. Study design: Doppler samples from proximal right pulmonary artery blood velocities and middle cerebral artery (MCA) were recorded cross-sectionally in 228 normal singleton pregnancies at gestational age 22 to 40 weeks. MCA / right pulmonary artery pulsatility index (PO ratio was calculated. Doppler samples from proximal right pulmonary artery and MCA were also recorded in 89 high-risk singleton pregnancies and the results related to perinatal outcome. Results: In the normal controls, right pulmonary artery PI remained stable until 30 weeks of gestation with slight increase thereafter until term. The MCA to right pulmonary artery PI ratio increased between 22 and 28 weeks of gestation with the rapid fall towards term. In the high-risk pregnancies group, right pulmonary artery PI showed no significant correlation to perinatal outcome, but signs of brain-sparing in the MCA were correlated to all adverse outcome parameters. Conclusion: Velocimetry of the middle cerebral artery is better than velocimetry of right pulmonary artery in predicting adverse outcome of pregnancy The brain/lung PI ratio does not improve the prediction of adverse outcome of pregnancy.
7.
Breborowicz, Andrzej, et al.
(författare)
Fetal pulmonary and cerebral artery Doppler velocumetry in normal and high risk pregnancy.
2014
Ingår i: Ginekologia Polska. - 0017-0011. ; 85:1, s. 26-30
Tidskriftsartikel (refereegranskat) abstract
Studies on fetal lung/brain circulation by means of power Doppler technique have suggested a marked reduction in lung perfusion in high-risk pregnancies as a sign of circulation redistribution. The ratio between lung/brain perfusion might therefore give a new method to predict fetal circulation centralization.
8.
Cheema, Riffat, et al.
(författare)
Multivascular Doppler surveillance in high risk pregnancies
2012
Ingår i: Journal of Maternal-Fetal & Neonatal Medicine. - : Informa UK Limited. - 1476-7058 .- 1476-4954. ; 25:7, s. 970-974
Tidskriftsartikel (refereegranskat) abstract
Objectives: Analysis of fetal arterial and venous Doppler predictability for adverse perinatal outcome. Methods: Blood flow in the uterine, umbilical and middle cerbral arteries, umbilical vein, ductus venosus and Galen vein were examined with in 72 h of delivery in 88 high-risk pregnancies. The managing clinicians were only informed about the results of the umbilical artery Doppler. The Doppler results were correlated to adverse perinatal outcome. Results: Doppler abnormalities were seen in both preterm and term pregnancies. Umbilical venous pulsations (n = 13) were strongly correlated to Apgar score <7 at 5 min, abnormal blood gases, need for ventilation assistance and operative delivery for fetal distress. Twenty-four fetuses had brain sparing in the middle cerebral artery, and forty-five had abnormal umbilical artery Doppler. These were correlated to admission in the neonatal intensive care unit, operative delivery and prematurity. Brain sparing in middle cerebral artery was also correlated to ventilation disturbances in the newborns. Abnormal ductus venosus blood velocity was only seen in 9 cases and not related to adverse outcome. Galen vein pulsations (n = 26) seem to appear earlier than pulsations in the umbilical vein and were not related to adverse outcome. conclusion: Umbilical vein pulsations were better correlated to adverse perinatal outcome than were other Doppler findings including ductus venosus.
9.
Dahlbäck, Charlotte, et al.
(författare)
Alterations in ductus venosus velocity indices in relation to umbilical venous pulsations and perinatal outcome.
2015
Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 1600-0412 .- 0001-6349.
Tidskriftsartikel (refereegranskat) abstract
Abnormal blood velocity in the ductus venosus is more frequently detected than pulsations in the umbilical vein, but both are considered indicators of fetal compromise. The aim of this study was to investigate blood flow patterns in the ductus venosus and the association between individual blood velocity ratios and pulsations in the umbilical vein and perinatal outcome.
10.
Dahlbäck, Charlotte, et al.
(författare)
Increased pulsatility in the fetal ductus venosus is not related to altered cardiac strain in high-risk pregnancies.
2016
Ingår i: Journal of Maternal-Fetal & Neonatal Medicine. - : Informa UK Limited. - 1476-7058 .- 1476-4954. ; 29:8, s. 1328-1333
Tidskriftsartikel (refereegranskat) abstract
Blood flow velocity patterns in fetal veins are considered to reflect cardiac function, but have not been convincingly documented. The aim of this study was to generate reference values for fetal cardiac strain and compare it with results in fetuses with signs of increased venous pulsatility.
