BACKGROUND
Histologic examination of the placentas from intrauterine growth retardation (IUGR) fetuses can supplement clinical knowledge of the cause of IUGR. The present study was undertaken to observe the pathologic findings regarding the placentas in IUGR fetuses.
METHODS
Clinicopathologic findings in 45 cases with IUGR at the third-trimester were reviewed, and they were compared with those of 24 normal control cases. An IUGR fetus was defined as one with a birth weight less than those in the 10th percentile. Of the IUGR cases, 15 were hypertensive IUGR with or without preeclampsia, and 30 were normotensive IUGR.
RESULTS
The IUGR groups had significantly shorter mean gestational ages, lower mean placental weights, and higher incidences of oligohydramnios, compared to the normal controls (p<0.05). Histologically, IUGR was characterized by increased incidence of decidual vasculopathy (31.1%, p<0.05), multiple and severe infarct (p<0.05), villous fibrosis (31.1%, p<0.05), syncytiotrophoblastic knots (86.7%, p<0.05), and higher degree of increased perivillous fibrin deposition (p<0.05). However, there were no statistically significant differences in the placental lesions between hypertensive and normotensive IUGR cases, except for the presence of decidual vasculopathy.
CONCLUSIONS
Abnormal uteroplacental vasculature and chronic uteroplacental insufficiency, coagulation-related pathology in the uteroplacental, intervillous and/or fetoplacental vasculature, and chronic inflammatory lesions may be the primary disease processes related to the placental pathology of IUGR. Although the cause of IUGR pregnancies is heterogeneous, careful cilinicopathologic correlations in individual cases are necessary in the interpretation of placental lesions of IUGR, and the total burden of several placental lesions may be more important than a single histologic feature.