Placental expression of soluble fms-like tyrosine kinase 1 is increased in singletons and twin pregnancies with intrauterine growth restriction.
OBJECTIVE
Intrauterine growth restriction (IUGR) is characterized by decreased placental perfusion. Low oxygen has been shown to increase soluble fms-like tyrosine kinase 1 (sFlt-1) expression in the human placenta. The objective of this study was to examine sFlt-1 expression in different types of IUGR pregnancies, including early-onset severe cases characterized by abnormal umbilical and uterine artery Doppler and discordant IUGR twins in which the normal cotwin represents the optimal control because both placentas share the same uterine environment.


METHODS
Placentas from four subgroups were collected: early severe IUGR with umbilical artery absent end diastolic flow (n = 19), small for gestational age with normal uterine and umbilical artery Doppler (n = 11), severely growth-restricted dichorionic and monochorionic twins with abnormal umbilical artery Doppler (n = 9), preeclamptic twins (n = 3), and age-matched normal singletons (n = 19) and twin controls (n = 8).


RESULTS
Expression of sFlt-1 mRNA and protein was significantly increased in IUGR placentas compared with small for gestational age and normal control placentas. sFlt-1 expression levels were also significantly greater in the small IUGR twin placentas from discordant twin pregnancies compared with the normal cotwin. In preeclamptic twins, sFlt-1 expression was increased in only one of the two placentas.


CONCLUSIONS
Our results demonstrate that sFlt-1 expression is increased in severe IUGR placentas with abnormal umbilical artery Doppler of singletons and also in discordant IUGR twins. Reduced placental perfusion may contribute to the increased expression of sFlt-1 in IUGR pregnancies. Our data are compatible with differential sFlt-1 expression in placentas from discordant twins.
Nevo
Ori
O
Department of Obstetrics and Gynecology, Mount Sinai Hospital, 600 University Avenue, Room 871C, Toronto, Ontario, Canada M5G 1X5.
Many
Ariel
A
Xu
Jing
J
Kingdom
John
J
Piccoli
Ettore
E
Zamudio
Stacy
S
Post
Martin
M
Bocking
Alan
A
Todros
Tullia
T
Caniggia
Isabella
I
D000328:Adult; D015153:Blotting, Western; D005260:Female; D005317:Fetal Growth Retardation / Q000201:enzymology*; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D010920:Placenta / Q000098:blood supply / Q000201:enzymology*; D011225:Pre-Eclampsia / Q000201:enzymology*; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014427:Twins; D018608:Ultrasonography, Doppler; D014469:Umbilical Arteries / Q000000981:diagnostic imaging; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000096:biosynthesis* / Q000235:genetics
C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1