501: Differences in neonatal outcome and placental pathology in relation to the severity of fetal growth restriction

Abstract

We aimed to investigate neonatal outcome and placental pathology in pregnancies complicated with small for gestational age (SGA) neonates, in relation to the severity of growth restriction and in comparison to appropriate for gestational age (AGA) neonates. The medical records and placental histology reports of all neonates with a birth-weight (BW) ≤10th percentile, born between 24-42 weeks of gestation, during 2010-2015, were reviewed. Placental lesions were classified into maternal and fetal vascular malperfusion (MVM and FVM) lesions, according to the Amsterdam classification. Results were compared between neonates with BW< 5th percentile (severe SGA group), neonates with BW between 5th-10th percentile (mild SGA group) and a control group of AGA neonates, adjusted to the study groups for gestational age (GA), maternal age, and mode of delivery. Composite neonatal outcome was defined as one or more of early complications. Overall, 753 neonates were included, 238 in the severe SGA group, 266 in the mild SGA group, and 249 in the control group. There were no differences in maternal age, maternal diabetes or thrombophilia, GA at delivery and mode of labor between the groups. In the severe SGA group there were higher rates of severe preeclampsia compared with the mild SGA and control groups (10.1% vs. 5.6% vs. 2.8%, respectively, p=0.003), and higher rates of composite adverse neonatal outcome compared with the mild SGA and control groups (37.2% vs. 17.6%, vs. 24.5%, respectively, p<0.001). Mean placental weight was significantly lower in the severe SGA group as compared to the mild SGA group as compared to the controls (323±82gr vs. 365±79gr vs. 471 ±107gr, respectively, p<0.001). The SGA groups was characterized by higher rates of placental MVM and FVM lesions, compared with controls (p<0.001 for both). After controlling for confounders, using a multivariate regression analysis, we found that as growth restriction was more severe there was an increased likelihood of detecting placental MVM and FVM lesions (table). Worse neonatal outcome and more placental maternal and fetal vascular malperfusion lesions correlate with the severity of fetal growth restriction in a 'dose dependent' manner.View Large Image Figure ViewerDownload Hi-res image Download (PPT)