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First‐trimester uterine artery resistance and maternal serum concentration of asymmetric dimethylarginine
Author(s) -
Prefumo F.,
Thilaganathan B.,
Whitley G. S.
Publication year - 2008
Publication title -
ultrasound in obstetrics and gynecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.202
H-Index - 141
eISSN - 1469-0705
pISSN - 0960-7692
DOI - 10.1002/uog.5243
Subject(s) - medicine , uterine artery , asymmetric dimethylarginine , vascular resistance , endocrinology , gestation , artery , pregnancy , hemodynamics , arginine , biology , biochemistry , genetics , amino acid
Objective Maternal serum levels of asymmetric dimethyl‐ arginine (ADMA), an endogenous inhibitor of endothelial nitric oxide synthase, are known to be increased in pregnant women with high‐resistance placental circulation in the second trimester. The aim of the present study was to investigate the relationship between uterine artery resistance and maternal serum ADMA concentrations in the first trimester. Methods Doppler ultrasound examination of the maternal uterine arteries was performed at 10–14 weeks' gestation. High resistance was defined as bilateral uterine artery notches and a mean resistance index > 95 th centile. Control cases were defined as those presenting with no notches and a mean resistance index < 95 th centile. ADMA concentrations were measured in maternal serum. Results Forty singleton pregnancies were examined, 21 with high uterine artery resistance and 19 controls. Three cases of pre‐eclampsia occurred, all in the high‐resistance group. The mean (SD) maternal serum ADMA concentration was 0.78 (44%) and 0.93 (56%) µmol/L in the high‐resistance and control groups, respectively ( P = 0.17). There was no statistically significant correlation between maternal serum ADMA and uterine artery resistance index (ρ = − 0.15, P = 0.36). Conclusions No significant difference was found in maternal serum ADMA between pregnancies with first‐trimester high‐resistance uterine artery blood flow and controls. While second‐trimester circulating ADMA may have a direct link with maternal endothelial function, in the first trimester the effect of ADMA may be mainly evident at the placental level, without consequently affecting maternal circulating concentrations of the substance. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.