Clinicopathologic correlation and interdependence of basic patterns of placental injury.

Placental lesions rarely occur in isolation and placental lesion multiplicity is associated with poorer pregnancy outcome than that of isolated lesions. As little is known about mutual relations of various patterns of placental injury simultaneously occurring in the same placentas, particularly in relation to gestational age, this retrospective observational analysis was undertaken to study those in a population of 2486 cases of the second half high-risk pregnancy dominated by fetal congenital anomalies. To this end, 23 independent clinical and 48 placental phenotypes were statistically compared among 6 basic patterns of placental injury: Group 1: acute inflammation, Group 2: chronic inflammation, Group 3: maternal vascular malperfusion, Group 4: fetal vascular malperfusion, large vessel, Group 5: fetal vascular malperfusion, distal villous, and Group 6: shallow placental implantation. All cases had E cadherin/CD34 immunostaining performed for the diagnosis of recent fetal vascular malperfusion. There was a significant overlap among the studied patterns and lesions of placental injury. Placental distal villous fetal vascular malperfusion and acute inflammation was most frequently statistically significantly associated with abnormal clinical conditions, while lesions of distal villous fetal vascular malperfusion and maternal vascular malperfusion with other placental lesions/patterns of injury. The double immunostaining was responsible for the fetal vascular malperfusion being the most common type of placental injury in this population of placentas. The acute inflammation best correlated with clinical condition in preterm pregnancy and distal villous fetal vascular malperfusion at term. Maternal vascular malperfusion plus the above two patterns of placental injury correlated best with other placental phenotypes in mid third trimester.