TY - CHAP M1 - Book, Section TI - Trisomy 13 A1 - Bianchi, Diana W. A1 - Crombleholme, Timothy M. A1 - D'Alton, Mary E. A1 - Malone, Fergal D. Y1 - 2015 N1 - T2 - Fetology: Diagnosis and Management of the Fetal Patient, 2e AB - Key PointsThird most common liveborn autosomal aneuploidy. Incidence is approximately 1 in 5000 livebirths.Sonographic findings include holoprosencephaly, abnormal midface, congenital heart defects, polydactyly, and echogenic kidneys. First trimester findings include increased nuchal translucency measurement, fetal tachycardia, and early onset growth restriction.Differential diagnosis includes pseudotrisomy 13, Meckel–Gruber syndrome, Bardet–Biedl syndrome, and Smith–Lemli–Opitz syndrome.Associated with increased lethality in utero, and increased incidence of preeclampsia.80% of patients have full trisomy 13; 20% have mosaicism or a translocation. If a translocation is demonstrated, parental chromosomes should be studied.Prognosis is uniformly poor. Median survival time is 7 to 10 days. Five to 10% of patients survive up to one year of age. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - obgyn.mhmedical.com/content.aspx?aid=1106401825 ER -