title: Expectant management in type II selective intrauterine growth restriction and abnormal cord insertion in monochorionic twins.
abstract: OBJECTIVE
  To assess perinatal outcome in type II monochorionic (MC) diamniotic twin pregnancies (DA) affected by selective intrauterine growth restriction (sIUGR) and abnormal cord insertion managed expectantly.
  
  
  METHODS
  A prospective longitudinal study from June 2008 and July 2011 on 24 MCDA sIUGR twins. sIUGR was defined as estimated fetal weight below the 10th percentile in one twin and was classified into three groups based on umbilical artery (UA) Doppler diastolic flow (I: presence; II: constantly absent/reverse (AEDF/ARED); III: intermittently absent or reverse). Marginal cord insertion was defined as insertion within 2 cm of the placental disc edge, and velamentous insertion as a cord insertion into the fetal membranes. Expectant management was chosen in these twins, and absent or reverse A wave in the ductus venosus (DV) was a criterion for delivery. Neonatal outcome was available for all twins delivered. Pathological examination and vascular cast of placentas were performed in all cases.
  
  
  RESULTS
  Fourteen twin pregnancies were type II sIUGR, and ten presented an abnormal umbilical cord insertion. Median gestational age (GA) at diagnosis of sIUGR was 18 weeks' gestation (range 16-20 weeks), and all sIUGR co-twins showed AEDF of UA at a median gestational age of 20 weeks (range 18-22 weeks). Median gestational age at delivery was 30 weeks (range 28-34 weeks) with a median birth weight of 1285 g (range 307-1725 g). pH at birth and base excess (BE) were normal in all IUGR co-twin (pH>7.10, median BE 5.5); Apgar score at 5 min was >7. Perinatal outcome was favorable in all cases. Placental pathological examination confirmed the marginal insertion of the umbilical cord and the absence of anastomosis between the two portions of umbilical insertion.
  
  
  CONCLUSIONS
  This study highlights that expectant management for sIUGR type II twins with or without an abnormal cord insertion should be a valid option to time delivery for these fetuses as shown by the favorable neonatal outcome.
authors.affiliation: Maternal Fetal Medicine Unit, Department of Woman and Child Health, University of Padua, Padua, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Visentin
authors.forename: Veronica
authors.initials: V
authors.lastname: Macchi
authors.forename: Francesca
authors.initials: F
authors.lastname: Grumolato
authors.forename: Andrea
authors.initials: A
authors.lastname: Porzionato
authors.forename: Raffaele
authors.initials: R
authors.lastname: De Caro
authors.forename: Erich
authors.initials: E
authors.lastname: Cosmi
mesh_terms: D000328:Adult; D002823:Chorion / Q000002:abnormalities* / Q000098:blood supply; D004200:Diseases in Twins / Q000145:classification / Q000473:pathology / Q000628:therapy*; D005260:Female; D005317:Fetal Growth Retardation / Q000145:classification / Q000473:pathology / Q000628:therapy*; D006801:Humans; D007231:Infant, Newborn; D008137:Longitudinal Studies; D011247:Pregnancy; D011256:Pregnancy Outcome; D011379:Prognosis; D011446:Prospective Studies; D014430:Twins, Monozygotic; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging; D014470:Umbilical Cord / Q000002:abnormalities* / Q000000981:diagnostic imaging