Relation of placental diagnosis in stillbirth to fetal maceration and gestational age at delivery

Aim: To study the relation of retention of dead fetus resulting in its maceration and gestational age at delivery to placental diagnosis. Methods: Some 75 clinicoplacental phenotypes have been retrospectively analyzed in 520 consecutive stillbirths, 329 macerated and 191 nonmacerated, and at three gestational age interval cohorts (330 second trimester, 102 preterm third trimester, and 88 term). Chi-square and clustering methods (Ward dendrograms and multidimensional scaling) were used for statistical analysis. Results: Maternal diabetes mellitus, induction of labor, fetal growth restriction, various umbilical cord abnormalities, and placental clusters of sclerotic/hemosiderotic chorionic villi were more common in macerated stillbirths, while clinicoplacental signs and symptoms of ascending infection and placental abruption, i.e., retro-placental hematoma, premature rupture of membranes, and acute chorioamnionitis in nonmacerated stillbirths. Placental abnormalities were less common in the second trimester, other than the acute chorioamnionitis. Patterns of chronic hypoxic placental injury were common in preterm third trimester, while signs of in-utero hypoxia (abnormal cardiotocography, meconium, and histological erythroblastosis of fetal blood) in term pregnancy. In addition to classical statistics, the clustering analyses added new information to placental investigation of cause of stillbirth. Conclusions: Macerated third trimester stillbirths have multifactorial etiology more likely than the second trimester stillbirths and the likely stasis-induced fetal thrombotic vasculopathy secondary to occult umbilical cord compromise should be sought in placental investigation in such cases. Nonmacerated stillbirths are associated with ascending infection and placental abruption.