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Fetal middle cerebral to uterine artery pulsatility index ratios in normal and pre-eclamptic pregnancies

Simanaviciute, D and Gudmundsson, Saemundur LU (2006) In Ultrasound in Obstetrics & Gynecology 28(6). p.794-801
Abstract
Objectives To calculate the normal range for the fetal middle cerebral artery (MCA)/uterine artery pulsatility index (PI) ratio in the third trimester of pregnancy and to assess its value, compared with that of the MCA/umbilical artery PI ratio, in predicting an unfavorable outcome of pregnancies complicated by pre-eclampsia. Methods Doppler blood flow velocimetry of the uterine and umbilical arteries and fetal MCA was performed. We calculated the ratios between 1) the PI of the MCA and the mean PI value of both uterine arteries and 2) the PI of the MCA and the PI of the umbilical artery. All women were examined at or beyond 26 weeks of gestation. A cross-sectional study of 231 normal pregnancies was conducted to construct the reference... (More)
Objectives To calculate the normal range for the fetal middle cerebral artery (MCA)/uterine artery pulsatility index (PI) ratio in the third trimester of pregnancy and to assess its value, compared with that of the MCA/umbilical artery PI ratio, in predicting an unfavorable outcome of pregnancies complicated by pre-eclampsia. Methods Doppler blood flow velocimetry of the uterine and umbilical arteries and fetal MCA was performed. We calculated the ratios between 1) the PI of the MCA and the mean PI value of both uterine arteries and 2) the PI of the MCA and the PI of the umbilical artery. All women were examined at or beyond 26 weeks of gestation. A cross-sectional study of 231 normal pregnancies was conducted to construct the reference range. Values below the 5(th) percentile or an MCA/umbilical artery PI ratio lower than 1.08 were defined as brain-sparing. A further 115 pregnancies with pre-eclampsia (50 mild and 65 severe) were assessed prospectively and the results were related to perinatal outcome. The accuracy of MCA/uterine artery and MCA/umbilical artery PI ratios for prediction of unfavorable pregnancy outcome was compared. Results Normal MCA/uterine artery PI ratios decreased with advancing gestational age. Redistribution of the fetal circulation indicated by a low MCA/uterine artery PI ratio was seen in 30% of the mild (n = 15) and 46% of the severe (n = 30) pre-eclamptic cases. There was a significant difference between those without and those with signs of brain-sparing, respectively, in mean birth weight (2456.0 vs. 1424.5 g), gestational age at delivery (35.6 vs. 31.3 weeks) and gestational age at the time of examination (34.9 vs. 30.9 weeks). Furthermore, there was a significantly higher rate of small-for-gestational-age (SGA) neonates (57.8% vs. 25.7%), preterm delivery (100% vs. 81.8%) and Cesarean section (90.7% vs. 66.7%) in cases with an MCA/uterine artery PI ratio below the 5th percentile. However, there was no difference between the groups in the rate of low 5-min Apgar scores, admission to the neonatal intensive care unit, or deliveries before 34 weeks. The MCA/uterine artery and MCA/umbilical artery PI ratios were similar in the prediction of adverse perinatal outcome. Both ratios were better at predicting the outcome of pregnancy than were signs of increased vascular impedance in either the umbilical or uterine arteries. Conclusions Normal MCA/uterine artery PI ratio decreases with gestational age. Abnormally low MCA/uterine artery PI ratios are related to unfavorable pregnancy outcome. The predictive value of the MCA/uterine artery PI ratio is similar to that of the MCA/umbilical artery PI ratio. Copyright (c) 2006 ISUOG. Published by John Wiley & Sons, Ltd. (Less)
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Contribution to journal
publication status
published
subject
keywords
pre-eclampsia, MCA/uterine artery PI ratio, brain-sparing, Doppler, redistribution, pregnancy
in
Ultrasound in Obstetrics & Gynecology
volume
28
issue
6
pages
794 - 801
publisher
John Wiley and Sons
external identifiers
  • wos:000242225300010
  • scopus:33751235575
  • pmid:17029308
ISSN
1469-0705
DOI
10.1002/uog.3805
language
English
LU publication?
yes
additional info
The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Pediatrics/Urology/Gynecology/Endocrinology (013240400)
id
d588ef51-8912-4bc9-8313-7712a0b1d384 (old id 376463)
date added to LUP
2016-04-01 15:29:55
date last changed
2021-09-22 04:42:35
@article{d588ef51-8912-4bc9-8313-7712a0b1d384,
  abstract     = {Objectives To calculate the normal range for the fetal middle cerebral artery (MCA)/uterine artery pulsatility index (PI) ratio in the third trimester of pregnancy and to assess its value, compared with that of the MCA/umbilical artery PI ratio, in predicting an unfavorable outcome of pregnancies complicated by pre-eclampsia. Methods Doppler blood flow velocimetry of the uterine and umbilical arteries and fetal MCA was performed. We calculated the ratios between 1) the PI of the MCA and the mean PI value of both uterine arteries and 2) the PI of the MCA and the PI of the umbilical artery. All women were examined at or beyond 26 weeks of gestation. A cross-sectional study of 231 normal pregnancies was conducted to construct the reference range. Values below the 5(th) percentile or an MCA/umbilical artery PI ratio lower than 1.08 were defined as brain-sparing. A further 115 pregnancies with pre-eclampsia (50 mild and 65 severe) were assessed prospectively and the results were related to perinatal outcome. The accuracy of MCA/uterine artery and MCA/umbilical artery PI ratios for prediction of unfavorable pregnancy outcome was compared. Results Normal MCA/uterine artery PI ratios decreased with advancing gestational age. Redistribution of the fetal circulation indicated by a low MCA/uterine artery PI ratio was seen in 30% of the mild (n = 15) and 46% of the severe (n = 30) pre-eclamptic cases. There was a significant difference between those without and those with signs of brain-sparing, respectively, in mean birth weight (2456.0 vs. 1424.5 g), gestational age at delivery (35.6 vs. 31.3 weeks) and gestational age at the time of examination (34.9 vs. 30.9 weeks). Furthermore, there was a significantly higher rate of small-for-gestational-age (SGA) neonates (57.8% vs. 25.7%), preterm delivery (100% vs. 81.8%) and Cesarean section (90.7% vs. 66.7%) in cases with an MCA/uterine artery PI ratio below the 5th percentile. However, there was no difference between the groups in the rate of low 5-min Apgar scores, admission to the neonatal intensive care unit, or deliveries before 34 weeks. The MCA/uterine artery and MCA/umbilical artery PI ratios were similar in the prediction of adverse perinatal outcome. Both ratios were better at predicting the outcome of pregnancy than were signs of increased vascular impedance in either the umbilical or uterine arteries. Conclusions Normal MCA/uterine artery PI ratio decreases with gestational age. Abnormally low MCA/uterine artery PI ratios are related to unfavorable pregnancy outcome. The predictive value of the MCA/uterine artery PI ratio is similar to that of the MCA/umbilical artery PI ratio. Copyright (c) 2006 ISUOG. Published by John Wiley & Sons, Ltd.},
  author       = {Simanaviciute, D and Gudmundsson, Saemundur},
  issn         = {1469-0705},
  language     = {eng},
  number       = {6},
  pages        = {794--801},
  publisher    = {John Wiley and Sons},
  series       = {Ultrasound in Obstetrics & Gynecology},
  title        = {Fetal middle cerebral to uterine artery pulsatility index ratios in normal and pre-eclamptic pregnancies},
  url          = {http://dx.doi.org/10.1002/uog.3805},
  doi          = {10.1002/uog.3805},
  volume       = {28},
  year         = {2006},
}