title: [Prognostic value of ultrasonography of the yolk sac in singleton pregnancy].
abstract: OBJECTIVE
  The aim of the research was evaluation of the clinical usefulness of chosen ultrasonographic morphological parameters of the yolk sac in the first trimester of unifetal pregnancies.
  
  
  METHODS
  Analysis has been done on 391 cases of unifetal pregnancies in the first trimester. Parameters of ultrasonographic evaluation: diameter, appearance and size of yolk sac, biometrics and fetal anatomy, confirmation of heart beating.
  
  
  CONCLUSIONS
  The yolk sac should be observed in the fifth week or when its biggest size equals to 10 mm in a normal pregnancy. Abnormal morphological appearance of the yolk sac and/or the size over 9 mm suggest serious growth disorders of the fetus or its necrobiosis. The yolk sac, apart from cases of hydatid mole, should be possible to be observed between 5-12 weeks of pregnancy.
authors.affiliation: Oddział Połoz.-Ginek. w Działdowie.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Roman
authors.forename: Witold
authors.initials: W
authors.lastname: Malinowski
mesh_terms: D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D005865:Gestational Age; D006801:Humans; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011379:Prognosis; D018709:Statistics, Nonparametric; D016216:Ultrasonography, Prenatal / Q000379:methods; D015017:Yolk Sac / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*