Is there a relationship between estimated fetal weight and umbilical artery Doppler impedance indices?

Full Abstract

OBJECTIVE: To establish whether there is a relationship between estimated fetal weight (EFW) and umbilical artery Doppler waveform impedance indices in the third trimester. METHODS: The pulsatility index (PI) and S/D (systolic/diastolic) ratio were obtained together with the EFW from 274 low-risk pregnancies. Measurements were made at fortnightly intervals from 30 weeks' gestation until delivery. A relationship between the two impedance indices and EFW was sought at gestational age ranges of 30-32, 33-35, 36-38 and 39-41 weeks. RESULTS: There were 918 pairs of PI (with S/D) and EFW available for analysis. The mean of the impedance indices decreased with advancing gestational age as expected. There was no clinically relevant correlation between impedance indices and EFW within any of the gestational age ranges. CONCLUSION: Impedance indices from the umbilical artery Doppler waveform decrease with advancing gestational age due, at least partially, to expansion of the placental vascular tree. Within narrow gestational age ranges in the third trimester, there is no meaningful correlation between fetal weight and impedance indices. It is therefore not necessary to adjust umbilical artery Doppler impedance indices to account for fetal size. Copyright 2003 ISUOG. Published by John Wiley & Sons, Ltd.

Author information

Author/s: Owen, P (P); Murphy, J (J); Farrell, T (T);

Affiliation: Department of Obstetrics, Princess Royal Maternity Unit, Alexandra Parade, Glasgow, Scotland, UK. philipowen1(-atsign-)hotmail.com

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology (Ultrasound Obstet Gynecol), published in England. (Language: eng)

Reference: 2003-Aug; vol 22 (issue 2) : pp 157-9

Dates: Created 2003/08/07; Completed 2003/10/14; Revised 2006/11/15;

PMID: 12905510, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article
(including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.