RT Book, Section
A1 Bianchi, Diana W.
A1 Crombleholme, Timothy M.
A1 D'Alton, Mary E.
A1 Malone, Fergal D.
SR Print(0)
ID 1106401982
T1 Triploidy
T2 Fetology: Diagnosis and Management of the Fetal Patient, 2e
YR 2015
FD 2015
PB McGraw-Hill Education
PP New York, NY
SN 978-0-07-144201-5
LK obgyn.mhmedical.com/content.aspx?aid=1106401982
RD 2024/04/24
AB Key  PointsOccurs  in  1%  to  2%  of  clinically  recognized  conceptions  but  only  1/10,000  livebirths.  Not  associated  with  advanced  maternal  age.Most  cases  are  69,  XXY  (60%)  or  69,  XXX  (37%);  only  3%  of  cases  are  69,XYY.In  the  type  I  phenotype  the  fetus  is  relatively  well  grown  with  a  large  cystic  placenta.In  the  type  II  phenotype  the  fetus  is  markedly  growth  restricted  with  a  disproportionately  large  head  and  a  small,  noncystic  placenta.One  third  of  cases  survive  beyond  15  weeks  and  are  associated  with  abnormal  maternal  serum  screen  results.The  longest  postnatal  survival  for  an  affected  infant  was  10frac12  months.