RT Book, Section
A1 Bianchi, Diana W.
A1 Crombleholme, Timothy M.
A1 D'Alton, Mary E.
A1 Malone, Fergal D.
SR Print(0)
ID 1106401184
T1 Malformations in Twins
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=1106401184
RD 2024/09/07
AB Key  PointsCongenital  malformations  occur  more  commonly  in  twins  as  compared  with  singleton  gestations  and  are  an  important  contributor  to  the  increased  perinatal  mortality  associated  with  multiple  gestations.The  incidence  of  congenital  anomalies  is  thought  to  be  more  common  in  monozygotic  compared  with  dizygotic  twin  pregnancies.Antenatal  ultrasound  examination  is  used  to  detect  malformations  in  twin  pregnancies.The  antenatal  natural  history  will  depend  on  the  malformation  diagnosed,  whether  or  not  it  is  discordant,  and  thechorionicity  of  the  pregnancy.The  management  will  be  influenced  by  the  type  of  abnormality,  whether  or  not  it  is  concordant,  the  gestational  age  when  diagnosed,  and  chorionicity.Counseling  of  parents  depends  on  the  type  of  abnormality  and  the  prognosis  for  the  anomalous  twin  as  well  as  on  the  likely  outcome  for  the  normal  co-twin.Three  management  options  are  available  in  this  situation:  expectant  management,  selective  termination  of  the  anomalous  fetus,  and  termination  of  the  entire  pregnancy.Expectant  management  of  a  twin  pregnancy  discordant  for  an  abnormality  is  associated  with  an  increased  risk  for  preterm  delivery.The  method  chosen  for  selective  termination  will  depend  on  chorionicity.  Intracardiac  injection  of  potassium  chloride  is  safe  in  dichorionic  twins,  while  cord  occlusive  techniques  are  necessary  for  monochorionic  pregnancies.Treatment  of  neonatal  twins  with  malformations  will  depend  on  the  particular  malformation.The  recurrence  risk  for  malformations  seen  in  twin  pregnancies  will  depend  on  the  specific  abnormality.