title: Amniocentesis in twin pregnancies.
abstract: OBJECTIVE
  To describe the experiences in diagnostic amniocentesis in twin pregnancies.
  
  
  METHODS
  The computerized database and medical records of pregnant women attending Maternal Fetal Medicine Unit of the hospital for diagnostic amniocentesis at 16-20 weeks gestation between January 1992 and December 2006 were retrospectively reviewed.
  
  
  RESULTS
  During 15 years of experience, 7,890 amniocenteses at 16-20 weeks gestation were performed for prenatal diagnosis, including 174 procedures in 87 twin pregnancies. The mean gestational age at the time of amniocentesis was 17.13 +/- 3.35 weeks. Preterm birth rate defined as the delivery before 36 gestational weeks was 36.24%. The total fetal loss rate was 5.17%, however, the procedure related fetal loss within 2 weeks after the procedure was 1.15%.
  
  
  CONCLUSIONS
  Based on our limited data and previous studies, we can counsel patients undergoing twin amniocentesis at mid-trimester that the fetal loss rate may be slightly higher than that of singleton amniocentesis.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Siraprapa
authors.initials: S
authors.lastname: Supadilokluck
authors.forename: Fuanglada
authors.initials: F
authors.lastname: Tongprasert
authors.forename: Theera
authors.initials: T
authors.lastname: Tongsong
authors.forename: Chanane
authors.initials: C
authors.lastname: Wanapirak
authors.forename: Wirawit
authors.initials: W
authors.lastname: Piyamongkol
authors.forename: Supattra
authors.initials: S
authors.lastname: Sirichotiyakul
authors.forename: Kasemsri
authors.initials: K
authors.lastname: Srisupundit
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology*; D000328:Adult; D000649:Amniocentesis / Q000009:adverse effects*; D005260:Female; D046689:Fetal Mortality; D006801:Humans; D011247:Pregnancy; D012189:Retrospective Studies; D014427:Twins