title: [Monochorionic twins after treatment of sterility using assisted reproduction methods].
abstract: OBJECTIVE
  The goal of this study has been to determine frequency of occurrence of monochorial twins within the study group consisting of 521 pregnancies conceived through the In Vitro Fertilization (IVF) programme.
  
  
  METHODS
  An observational study.
  
  
  METHODS
  Sanatorium Pronatal, Na Dlouhé mezi 4/12, 147 00 Praha 4-Hodkovicky.
  
  
  METHODS
  A condition to be included in the study group was that there was a gestation sac detected by ultrasound. The first ultrasound examination was performed transvaginally and was done between the fifth and the sixth week of each pregnancy. A multiple pregnancy has been classified as monochorial in case when gestation sac contains two yolk sacs and two fetuses.
  
  
  RESULTS
  Within the whole study group there were 13 monochorial twins which presents 2.5% of all pregnancies. The incidence of monochorionicity among all multiple pregnancies is 6.4%, in IVF cycles without micromanipulation techniques the occurrence of monochorial twins has been 0.9%, following cryoembryotransfer 3.9%, with micromanipulation (ICSI, AH) it reaches 5.7% of all pregnancies.
  
  
  CONCLUSIONS
  Monochorial twins were detected seven time more frequent in comparison within occurrence in ordinary population. The occurrence rises in connection with the number of fetuses in uterus. In comparison with simple IVF cycles we have proved higher occurrence of monochorionicity in connection with micromanipulation techniques and cryoembryotransfer.
authors.affiliation: Sanatorium Pronatal, Praha.
authors.forename: J
authors.initials: J
authors.lastname: Hulvert
authors.forename: T
authors.initials: T
authors.lastname: Mardesic
authors.forename: P
authors.initials: P
authors.lastname: Müller
authors.forename: J
authors.initials: J
authors.lastname: Voboril
authors.forename: M
authors.initials: M
authors.lastname: Miková
authors.forename: R
authors.initials: R
authors.lastname: Hüttelová
authors.forename: V
authors.initials: V
authors.lastname: Becvárová
authors.forename: S
authors.initials: S
authors.lastname: Jirsová
mesh_terms: D002823:Chorion / Q000000981:diagnostic imaging*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D011247:Pregnancy; D011272:Pregnancy, Multiple; D014430:Twins, Monozygotic; D016216:Ultrasonography, Prenatal