Abnormal Lie and Presentation Definitions Lie the relationship

Abnormal Lie and Presentation

Definitions Lie: the relationship of the long axis of the fetus with that of the mother e. g. longitudinal, transverse, oblique Presentation: the part of the fetus that occupies the lower segment of the uterus e. g. cephalic, breech, shoulder Presenting part: the lowest part of the fetus that is palpable on vaginal examination e. g. vertex, brow, face, buttocks, foot, acromion Position: the relationship of the denominator of the presenting part to the maternal pelvis

Definitions Vertex: the area of the fetal skull that is bordered by the anterior fontanelle, the posterior fontanelle and the parietal eminences Engagement: the state when the widest diameter of the fetal presenting part enters the maternal pelvis Station: descent of the presenting part measured in centimeters above or below the level of the ischial spines Descent: this is the fifth of the presentation palpable above the pubic symphysis

Definitions Attitude: the degree of flexion of the fetal head(e. g. vertex, brow or face) Moulding: the reduction in the diameters of the fetal head caused by the coming together, or overlapping, of the sutures in the fetal skull as the head is compressed by the maternal pelvis Caput: localized swelling of the fetal scalp secondary to pressure during labour.

Abnormal Lie Transverse Oblique

Abnormal presentations Breech (extended, complete, footling) Shoulder Compound Deflexed head (Brow, Face)

Complete breech presentation

Frank breech presentation

Footling breech presentation

Brow Presentation

Face Presentation

CORD PRESENTATION/CORD PROLAPSE Cord presentation is when the cord presents with an intact membrane; usually in a transverse, oblique or breech presentations. Cord prolapse is when the cord descends below the presenting part following ruptured membranes; it poses a greater risk to the fetus.

COMPOUND PRESENTATION Compound presentation occurs when an arm prolapses alongside the presenting part. Both the prolapsed arm and the fetal head present in the pelvis simultaneously. Spontaneous delivery can occur only when the fetus is very small or dead and macerated. Arrested labour occurs in the expulsive stage.

Predisposing factors Prematurity Multiple pregnancy Uterine abnormalities Abnormal placental position Short umbilical cord Maternal pelvic abnormalities Grandmultiparity Laxity of the abdominal Abnormal liquor volume