Perinatal outcomes and placental histology in small‐for‐gestational‐age pregnancies—A comparison of population‐based and universal growth charts

Abstract

Objective To assess obstetric, perinatal, and placental histologic findings in small‐for‐gestational‐age (SGA) neonates according to different growth charts. Methods A retrospective cohort of singleton deliveries from 2008 to 2019 were divided into SGA neonates according to the local population‐based chart, SGA according to universal standard growth charts (but appropriate for gestational age [AGA] according to local charts) and AGA deliveries according to both charts. Results A total of 626 local population SGA deliveries, 132 universal SGA and 468 AGA deliveries were compared. The local population SGA group had a significantly higher rate of preterm and cesarean deliveries. An adverse neonatal outcome occurred in 27.2% of the local population SGA group, 9.8% of the universal SGA group and 6.7% of the AGA group (P < 0.001). In the local population SGA group, placental weight was lower, birth weight to placental weight ratio was highest, and the rate of maternal malperfusion lesions was highest—55.4% versus 45.4% in the universal SGA group and 39.1% in the AGA group (P < 0.001). Villitis of unknown etiology was significantly more common and histologic chorioamnionitis was significantly less common in the local population SGA group. Conclusions Our findings support the use of a local population‐based growth chart for the diagnosis of fetal growth restriction.