Association between placental pathology and early-onset fetal growth restriction: a systematic review

Abstract

Objective: Fetal growth restriction (FGR) is defined as the failure of the fetus to achieve its genetically determined growth potential, mainly caused by placental dysfunction. Previous studies have shown that early- and late-onset FGR could have a different histopathology background. Our aim is to compare the placental lesions present in early-onset fetal growth restriction with that of late-onset FGR. Study design: We performed a systematic review according to the PRISMA guideline. Observational studies, only in singleton pregnancies, evaluating the association between fetal growth restriction and placental lesions in early- versus late-onset FGR were included. A qualitative analysis was undertaken. The risk of bias was assessed using the NIH Study Quality Assessment Tool. Results: We included six articles. All studies showed a higher rate of maternal vascular malperfusion (MVM) lesions in the early-onset FGR groups when compared to late-onset ones. Only one study reported that fetal vascular malperfusion (FVM) and villitis of unknown etiology (VUE) were higher in early-onset FGR. Two studies found that fetal/placental weight ratio is lower in the early-onset group. Five articles reported that early-onset FGR is often associated with pre-eclampsia. Conclusion: This review shows that early-onset FGR cases are associated with specific placental histopathology, such as maternal vascular malperfusion lesions. Future studies should explore the role of the placenta on the pathogenesis of FGR. Placental histopathological examination is important to better understand the pathophysiology of FGR and can contribute to a better management of FGR. The study of placenta is useful to determine the risk of recurrence in subsequent pregnancies.