Biomaterial Database

Influence of the pelvic outlet capacity on fetal head presentation at delivery. 1987

J Floberg, and P Belfrage, and H Ohlsén

The influence of pelvic outlet capacity on fetal head presentation in 1,402 term primiparas with normal pregnancies was studied. In all cases radiological pelvimetry was carried out and labor started spontaneously. Occiput posterior (OP) delivery occurred in 5.1%. As pelvic outlet capacity decreased an increased frequency of OP presentations and need for epidural anesthesia (EDA) was found. With OP presentation the duration of labour was longer, the frequency of EDA, instrumental delivery, cesarean section and low Apgar score at 1 minute were all higher, all compared with occiput anterior (OA) presentation. No difference in fetal morbidity was found. When the influence of the pelvic outlet capacity was eliminated through comparison of matched groups, the course of delivery became more similar whether the presentation was OA or OP and the frequency of EDA became the same. Reduced pelvic outlet capacity seemed to be one cause of both OP presentation and the use of EDA.

UI	MeSH Term	Description	Entries
D007231	Infant, Newborn	An infant during the first 28 days after birth.	Neonate,Newborns,Infants, Newborn,Neonates,Newborn,Newborn Infant,Newborn Infants
D007746	Labor Presentation	The position or orientation of the FETUS at near term or during OBSTETRIC LABOR, determined by its relation to the SPINE of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the NECK.	Fetal Presentation,Presentation, Fetal,Fetal Malpresentation,Fetal Malpresentations,Malpresentation, Fetal,Presentation, Labor
D010298	Parity	The number of offspring a female has borne. It is contrasted with GRAVIDITY, which refers to the number of pregnancies, regardless of outcome.	Multiparity,Nulliparity,Primiparity,Parity Progression Ratio,Parity Progression Ratios,Ratio, Parity Progression,Ratios, Parity Progression
D010387	Pelvimetry	Measurement of the dimensions and capacity of the pelvis. It includes cephalopelvimetry (measurement of fetal head size in relation to maternal pelvic capacity), a prognostic guide to the management of LABOR, OBSTETRIC associated with disproportion.	Cephalopelvic Proportion,Cephalopelvimetry,Cephalopelvic Proportions,Cephalopelvimetries,Pelvimetries,Proportion, Cephalopelvic,Proportions, Cephalopelvic
D010388	Pelvis	The space or compartment surrounded by the pelvic girdle (bony pelvis). It is subdivided into the greater pelvis and LESSER PELVIS. The pelvic girdle is formed by the PELVIC BONES and SACRUM.	Pelvic Region,Region, Pelvic
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000767	Anesthesia, Epidural	Procedure in which an anesthetic is injected into the epidural space.	Anesthesia, Extradural,Anesthesia, Peridural,Epidural Anesthesia,Anesthesias, Epidural,Anesthesias, Extradural,Anesthesias, Peridural,Epidural Anesthesias,Extradural Anesthesia,Extradural Anesthesias,Peridural Anesthesia,Peridural Anesthesias
D000773	Anesthesia, Obstetrical	A variety of anesthetic methods such as EPIDURAL ANESTHESIA used to control the pain of childbirth.	Anesthesia, Gynecological,Anesthesia, Obstetric,Gynecologic Anesthesia,Paracervical Block,Anesthesia, Gynecologic,Block, Paracervical,Blocks, Paracervical,Gynecological Anesthesia,Obstetric Anesthesia,Obstetrical Anesthesia,Paracervical Blocks