VP20.05: Umbilico-porto-systemic shunt and fetal growth restriction: a novel etiology or guilty by association? A lesson from a prospective study

to determine the prevalence of fetal umbilico-porto-systemic venous shunts (UPSVS) in fetal growth restriction (FGR); to compare the perinatal outcome in FGR pregnancies with and without UPSVS; to determine the association between UPSVS and other anomalies in growth restricted fetuses. A prospective cross-sectional study of all pregnancies diagnosed with FGR according to the Delphi survey expert consensus (2016). All participants underwent a detailed anomaly scan, including a targeted scan of the fetal portal system. Shunts detected using colour Doppler were classified as extra- hepatic, intra-hepatic or umbilico-systemic. Perinatal outcome was compared between cases with and without UPSVS. 99 cases of FGR were included. The prevalence of UPSVS in our cohort was 8% (8/99). The median gestational age (GA) of FGR diagnosis and GA at delivery were 32.6 (IQR: 28.9-36.6) vs. 33.6 (30.3-35.5) (p = 0.82) and 35 (31.1-37.4) vs. 37 (35.3-37.3) (p=0.40) weeks, in the shunt and non-shunt group, respectively. The rate of preterm delivery was 50% vs. 46% (p = 0.83), in the shunt vs. non-shunt groups. Associated fetal vascular anomalies were significantly higher in the shunt group (50% vs. 8.8% p = 0.001). The rate of other associated anomalies was similar. The shunt group had a lower rate of abnormal uterine artery Doppler (0% vs. 40.7% p = 0.03). Other Doppler indices and NICU admission rates had non-significant difference. There was one case of stillbirth in each group, and one case of genetic aberration in the entire study population. UPSVS is a relatively common finding in growth restricted fetuses. Meticulous sonographic evaluation of the portal system and other vascular anomalies should be considered in the prenatal workup of FGR, as UPSVS may have implications during infancy and childhood, Short term perinatal outcome is comparable between FGR fetuses with and without UPSVS.