Human Placental Genomic Instability Predicts Adverse Pregnancy Outcomes

Preeclampsia is a leading cause of pregnancy-related death, accounting for over 50,000 maternal and 500,000 fetal deaths worldwide each year. Preeclampsia has been linked to confined placental mosaicism, which underscores a potential role of placental genomic instability in driving adverse pregnancy outcomes. Here, using bulk RNA sequencing from 59 preeclamptic and 53 normotensive pregnancies, we explored somatic genomic instability and hypoxia with respect to clinical maternal-placental-neonatal outcomes. We found that genomic instability increased the probability of delivering at an earlier gestational age with a diagnosis of preeclampsia, maternal vascular malperfusion placental lesions, and small for gestational age neonates. Notably, genomic instability and hypoxia are predictive biomarkers for all three adverse pregnancy outcomes. In an induced pluripotent stem cell-derived trophoblast stem cell model, we observed increased genomic instability in trophoblast stem cells obtained from placentas demonstrating maternal vascular malperfusion with preeclampsia. Additionally, increased genomic instability correlated with reduced extravillous trophoblast invasion, implicating a functional role for genomic instability. These findings provide promising insights into the underlying mechanisms of genomic instability in the placenta which may be useful biomarkers for early clinical diagnosis of placental injury underlying preeclampsia.