Failure of physiologic transformation of the spiral arteries in patients with preterm labor and intact membranes.
OBJECTIVE
The purpose of this study was to determine whether abnormal placentation (defined as the failure of physiologic transformation of spiral arteries) is present in patients with preterm labor and intact membranes who delivered a preterm neonate.


METHODS
A cross-sectional study was conducted to examine the histopathologic findings in the placental bed and placenta of patients with preterm labor and intact membranes (n=27), preeclampsia (n=43), and healthy pregnant women at term (n=103). Immunohistochemistry studies with cytokeratin 7 and periodic acid-Schiff were used to detect trophoblast and fibrinoid, respectively, and diagnose the failure of physiologic transformation of the spiral arteries.


RESULTS
The mean percentage of spiral arteries with failure of physiologic transformation in the myometrium was significantly higher in patients with preterm labor and preeclampsia than in normal pregnant women at term (P=.0004 and P<.0001, respectively). Similar findings were observed in the decidual segment of spiral arteries within the placental bed (P=.001 and P<.0001). In contrast, the mean percentage of the spiral arteries with failure of physiologic transformation in the decidua of the basal plate was not significantly different between patients with preterm labor and normal pregnant women (P=.17).


CONCLUSIONS
Failure of physiologic transformation of the spiral arteries in the myometrial and decidual segments of the placental bed is frequent in patients with preterm labor and intact membranes.
Perinatology Research Branch, National Institute of Child Health and Human Development (NIH/DHHS), Bethesda, MD, USA.
Yeon Mee
YM
Kim
Emmanuel
E
Bujold
Tinnakorn
T
Chaiworapongsa
Ricardo
R
Gomez
Bo Hyun
BH
Yoon
Howard T
HT
Thaler
Siegfried
S
Rotmensch
Roberto
R
Romero
D000328:Adult; D001158:Arteries / Q000473:pathology; D003430:Cross-Sectional Studies; D003656:Decidua / Q000473:pathology; D005321:Extraembryonic Membranes; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053552:Keratin-7; D007633:Keratins / Q000032:analysis; D009215:Myometrium / Q000473:pathology; D007752:Obstetric Labor, Premature / Q000473:pathology*; D010503:Periodic Acid-Schiff Reaction; D010920:Placenta / Q000098:blood supply* / Q000737:chemistry / Q000473:pathology; D011225:Pre-Eclampsia / Q000473:pathology; D011247:Pregnancy; D014327:Trophoblasts / Q000473:pathology
C507497:KRT7 protein, human; D053552:Keratin-7; D007633:Keratins