title: [Why are most children born from I. cephalic presentation?].
abstract: The question, why most children are delivered in I. cephalic position, is unsolved up to now. Most children are positioned with crossed legs in the uterus. Ultrasonography was employed from the 36th week of gestation onwards to find out whether there is a connection between crossing of the legs and the position in utero. From 58 pregnancies with I. position in 47 cases and from 32 pregnancies with II. position in 28 cases, the leg nearer to the back of the mother was crossed over the other one. According to the neuro-cerebral differentiation between both sides, the foetus prefers a crossing in such a manner, that the left leg is folded over the right leg. The foetus finds a more stable position, if the more mobile leg is directed with the foot against the yielding belly walls of the mother. In accordance with the preferred crossing of the left leg over the right leg the I. position in utero is more frequent.
authors.affiliation: Geburtshilflich-gynäkologische Abteilung, Städtisches Krankenhaus Lörrach.
authors.forename: B
authors.initials: B
authors.lastname: Warkentin
mesh_terms: D005260:Female; D005324:Fetal Movement / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007746:Labor Presentation; D011247:Pregnancy; D012016:Reference Values; D016216:Ultrasonography, Prenatal
vernacular_title: Warum werden die meisten Kinder aus I. Schädellage geboren?