Possible explanation of cephalic and noncephalic presentation during pregnancy: a theoretical approach.
This paper is based on fact that the fetus is exposed to gravity. The hypothesis is that from the 24th week of gestation an increasing percentage of fetuses occupies an exclusively cephalic presentation, since it allows an uncompromised posture in the caudal direction of body segments whose muscles are first affected by the occurrence and progressive increase of tone. Being in cephalic presentation, in a caudal direction, the fetus relieves body segments of the weight of the hypotonic-atonic part of the body in the cranial direction. In other words, cephalic presentation presents a body axis posture along the line of gravity. When the body axis posture along gravity is absent, the fetus simply fills the intrauterine cavity. In many such cases, the results are transverse lie, breech presentation and also cephalic presentation.
Sekulić
S R
SR
Department of Epilepsy and Child Neurology, Institute of Neurology, Psychiatry and Mental Health, Clinical Centre, Novi Sad, Yugoslavia. turija@Eunet.yu
D000818:Animals; D005260:Female; D006112:Gravitation; D006257:Head / Q000196:embryology; D006801:Humans; D007746:Labor Presentation; D011247:Pregnancy; D016216:Ultrasonography, Prenatal