ESPE Abstracts

Context: Silver-Russell syndrome (SRS) is a rare imprinting disorder responsible for foetal and postnatal growth restriction. It is a clinical diagnosis based on Netchine-Harbison clinical scoring system in patients presenting with ≥ 4 items out of 6. Some of the items in this score are not assessable until the age of two years, such as growth retardation or feeding difficulties and body asymmetry can be difficult to identify in the first months of life. Children born small for gestational age (SGA) due to SRS have a different evolution than children born SGA due to placental insufficiency and require appropriate follow-up and management. It is therefore important to make the diagnosis of SRS as early as possible. Objective: to determine the perinatal characteristics to differentiate between children born with severe foetal growth retardation due to placental insufficiency and children with SRS, to allow earlier clinical and/or molecular diagnosis of SRS and subsequent management.

Methods: We retrospectively compared the perinatal characteristics of children with SRS (n=17) with those of children born SGA by placental insufficiency (n=22).

Results: Children with SRS have earlier and more severely altered foetal weight and length than those born SGA due to placental insufficiency from the second trimester of pregnancy. The presence of uterine artery Doppler anomalies, a parameter classically used to orient the cause of foetal growth restriction towards placental vascular insufficiency, did not rule out the diagnosis of SRS, since 23% of patients with SRS had vascular anomalies. SRS children were significantly smaller at birth (birth length <-3DS in 77% of cases in the SRS group versus 15% in the placental insufficiency group, P=0.0001) with relative macrocephaly in 100% of cases in SRS children versus 59% in those born SGA by placental insufficiency (P=0.002).

Conclusion: The diagnosis of SRS must be evoked in the neonatal period in newborns SGA presenting a growth delay present from the second trimester of pregnancy with a birth length lower than -3 DS and a relative macrocephaly. Doppler anomalies must not systematically drive to placental vascular insufficiency diagnosis. Other clinical signs in favour of the diagnosis such as a protruding forehead and body asymmetry may be present from birth.