Placental transcriptional and histologic subtypes of normotensive fetal growth restriction are comparable to preeclampsia

• Published in: American journal of obstetrics and gynecology 2019-01, Vol.220 (1), p.110.e1-110.e21
• Main Authors: Gibbs, Isaac, Leavey, Katherine, Benton, Samantha J., Grynspan, David, Bainbridge, Shannon A., Cox, Brian J.
• Format: Article
• Language: English
• Subjects: clustering; fetal growth restriction; gene expression; histopathology; hypertension; microarray; placenta; preeclampsia; small-for-gestational-age
• ISSN: 0002-9378; 1097-6868
• DOI: 10.1016/j.ajog.2018.10.003

Infants born small for gestational age because of pathologic placenta-mediated fetal growth restriction can be difficult to distinguish from those who are constitutionally small. Additionally, even among fetal growth–restricted pregnancies with evident placental disease, considerable heterogeneity in clinical outcomes and long-term consequences has been observed. Gene expression studies of fetal growth–restricted placentas also have limited consistency in their findings, which is likely due to the presence of different molecular subtypes of disease. In our previous study on preeclampsia, another heterogeneous placenta-centric disorder of pregnancy, we found that, by clustering placentas based only on their gene expression profiles, multiple subtypes of preeclampsia, including several with co-occurring suspected fetal growth restriction, could be identified. The purpose of this study was to discover placental subtypes of normotensive small-for-gestational-age pregnancies with suspected fetal growth restriction through the use of unsupervised clustering of placental gene expression data and to investigate their relationships with hypertensive suspected fetal growth–restricted placental subtypes. A new dataset of 20 placentas from normotensive small-for-gestational-age pregnancies (birthweight