Placental mesenchymal dysplasia is associated with high rates of intrauterine growth restriction and fetal demise: A report of 11 new cases and a review of the literature.

Placental mesenchymal dysplasia (PMD) is a rare condition of placentomegaly and abnormal chorionic villi often clinically mistakenly as partial hydatidiform mole. However, it is clinicopathologically distinct with high incidence of intrauterine growth restriction (IUGR) and fetal death. This study presents 11 new PMD cases and provides a meta-analysis of the associated IUGR and fetal death rates. The cases were identified between 1971 and 2005, mostly from consultation files. To our knowledge, 71 PMD cases have previously been reported; 15 of these were associated with Beckwith-Wiedemann syndrome (BWS). With the addition of our new results, among all cases without BWS, 50% had IUGR and 43% had intrauterine fetal demise (IUFD) or neonatal death. Females represented 82% of cases. Thus, PMD is associated with high IUGR and IUFD/neonatal death rates and disproportionally affects females. The cause and pathogenesis are yet unknown. The current understanding and hypotheses involving PMD are discussed.