Objective: We aimed to study the placental component in early- and late-onset fetal growth restriction (FGR) compared to placentas from neonates appropriate for gestational age (AGA).

Study Design: Placentas from normotensive women who delivered neonates with birth-weight <10th percentile (FGR group), and placentas from healthy women who delivered AGA neonates (AGA group), between 24-42 weeks of gestation, were analyzed by a single pathologist. Placental lesions were classified to lesions consistent with maternal underperfusion, lesions consistent with fetal thrombo-occlusive disease and inflammatory lesions. Findings were compared between patients who delivered ≤ 34 weeks (early-onset FGR) or > 34 weeks (late-onset FGR) and controls with AGA neonates.

Results: The early-onset FGR group (n=24) was characterized by a higher rate of vascular lesions related to maternal underperfusion, 41.7% vs. 8.7% than in the late-FGR group (n=334), p<0.001. Compared to AGA controls delivered ≤34 weeks (n=68), the early-onset FGR group had more villous lesions related to maternal underperfusion, 70.8% vs. 5.9%, P <0.001, and less inflammatory lesions, 8.3% vs. 58.8%, p<0.001. Placentas from late-onset FGR group had more villous lesions related to maternal underperfusion, 57% vs. 19%, p<0.001, and more fetal vascular supply lesions consistent with fetal thrombo-occlusive disease, 26.3% vs. 8.5%, p<0.001, compared with AGA controls (n=153) delivered >34 weeks.

Conclusion: Early- and late-onset FGR have different placental pathology compared with AGA controls, suggesting that a combination of fetal and maternal vascular compromise is more dominant in the late-onset FGR, rather than more severe maternal vascular compromise in early-onset FGR.

Authors:

Michal Kovo 1, Letizia Schreiber 2, Avi Ben-Haroush 3,

Guy Cohen1, Eran Weiner 1, Abraham Golan 1, Jacob Bar 1

Department of Obstetrics & Gynecology 1 and Department of Pathology 2, the Edith Wolfson Medical Center, Holon and the Department of Obstetrics & Gynecology Rabin Medical Center 3, Petach-Tikva; affiliated with Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv; Israel