Functional magnetic resonance imaging (magnetization transfer) and stereological analysis of human placentae in normal pregnancy and in pre-eclampsia and intrauterine growth restriction.
Magnetic resonance imaging provides a non-invasive method for investigating functional changes in the human placenta in vivo. In this study, we combine a magnetic resonance imaging technique called magnetization transfer with established stereological methods in order to analyse and compare placentae from normal (16-36 weeks of gestation) and complicated (pre-eclampsia, intrauterine growth restriction) pregnancies. Magnetization transfer provided an in vivo measure of the ratio of bound protons:total protons and stereological analysis of histological sections was used to estimate a residual:total volume ratio (the ratio of non-vascular volume to total placental volume). Statistical comparisons were drawn using tests for related samples (longitudinal data) or one-way analysis of variance (cross-sectional data). We found no significant differences in magnetization transfer between gestational age groups or between uncomplicated pregnancies and pregnancies complicated by pre-eclampsia or intrauterine growth restriction. In comparable groups of different subjects, stereological analyses also failed to demonstrate significant differences in residual:total volume ratios. We conclude that [a] the ratio of non-vascular volume:total placental volume does not alter between 16 and 36 weeks of normal gestation, and [b] this integrated response is also conserved in pre-eclampsia and intrauterine growth restriction.
Ong
S S
SS
Department of Obstetrics and Gynecology, School of Human Development, City Hospital, University of Nottingham, Hucknall Road, Nottingham NG5 1PB, UK. stephenong888@hotmail.com
Tyler
D J
DJ
Moore
R J
RJ
Gowland
P A
PA
Baker
P N
PN
Johnson
I R
IR
Mayhew
T M
TM
D001724:Birth Weight; D001808:Blood Vessels / Q000473:pathology; D003627:Data Interpretation, Statistical; D017352:Echo-Planar Imaging / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005317:Fetal Growth Retardation / Q000473:pathology*; D005865:Gestational Age; D006801:Humans; D008137:Longitudinal Studies; D018579:Patient Selection; D010920:Placenta / Q000473:pathology*; D021041:Placental Circulation; D011225:Pre-Eclampsia / Q000473:pathology*; D011247:Pregnancy