Leeds Fetal Medicine Unit Website

Edward's Syndrome (Trisomy 18)

Definition	Additional chromosome 18 resulting in 47 rather than 46 chromosomes
Incidence	1:3000 livebirths increasing with maternal age
Diagnosis	Can only occur after karyotyping Ultrasound features that are suggestive Increased nuchal translucency 11-14 weeks (CRL 45-84mm) CPCs Mega cisterna magna Congenital Diaphragmatic Hernia Omphalocele Musculoskeletal abnormalities (clenched fists, Talipes, Rockerbottom feet, Radial ray malformation) Cardiac abnormalities Renal abnormalities Two vessel cord Polyhydramnios IUGR
Gestation at diagnosis	11 weeks onwards
Known chromosomal or genetic association	Yes trisomy 18
Further investigations	Karyotype for diagnosis
Differential Diaganosis	Trisomy 13 Smith-Lemli-Opitz syndrome Pena-Shokeir syndrome (pseudo-trisomy 18)
Prognosis	Most do not survive pregnancy 90% die in first year of life, those that do survive have severe learining difficulties
Recurrance risk	Low (~1%)
Research Studies

Further information for clinicians please click here

Patient information leaflet please click here

Link to S.O.F.T ( a website designed to deal with issues around Edward's and Patau's sundrome; please click here)

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