title: Second trimester amniocentesis in assisted conception versus spontaneously conceived twins.
abstract: OBJECTIVE
  To compare the outcome of amniocentesis in twins conceived with assisted reproduction technology (ART) versus spontaneously conceived twins.
  
  
  METHODS
  Retrospective analysis of case records between 1993 and 2006.
  
  
  METHODS
  University-affiliated tertiary center for fetal medicine.
  
  
  METHODS
  167 ART twin pregnancies and 275 spontaneous twin pregnancies.
  
  
  METHODS
  Genetic amniocentesis.
  
  
  METHODS
  Comparison of pregnancy loss rate and perinatal outcome between the ART and spontaneous twin-pregnancy groups.
  
  
  RESULTS
  The fetal loss rate was similar between the two groups (4.2% vs. 4.0% in the ART twins and spontaneous twins, respectively), although the interval between amniocentesis to miscarriage was statistically significantly shorter in the ART twins than the spontaneous twins (6.2 and 20.1 days, respectively). In all cases, fetal loss refers to the loss of the entire pregnancy. The preterm delivery rate before 37 weeks was statistically significantly higher in the ART group (64.1%) compared with controls (49.5%).
  
  
  CONCLUSIONS
  Amniocentesis in ART twins carries a fetal loss rate similar to spontaneous twins. However, ART twins have a statistically significantly increased risk of preterm delivery especially before 32 weeks' gestation.
authors.affiliation: First Department of Obstetrics and Gynecology, Alexandra Maternity Hospital, Athens University, Athens, Greece. gdaskalakis@yahoo.com
authors.forename: George
authors.initials: G
authors.lastname: Daskalakis
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Anastasakis
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Papantoniou
authors.forename: Spyros
authors.initials: S
authors.lastname: Mesogitis
authors.forename: Aris
authors.initials: A
authors.lastname: Antsaklis
mesh_terms: D000649:Amniocentesis / Q000379:methods*; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011262:Pregnancy Trimester, Second; D027724:Reproductive Techniques, Assisted / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012306:Risk; D014427:Twins / Q000502:physiology*