Download - Face presentation
FACE PRESENTATION
k.gayatri
DEFINITION: This is a rare variety of cephalic presentation where
presenting part: is face attitude: complete flexion of
limbs with extension of spine so that occiput is in contact with back denominator: mentum
POSITIONRIGHT OCCIPITO POSTERIOR
LEFT MENTO ANTERIOR
LEFT OCCIPITO POSTERIOR RIGHT MENTO ANTERIOR
RIGHT OCCIPITO ANTERIOR LEFT MENTO POSTERIOR
LEFT OCCIPITO ANTERIOR RIGHT MENTO POSTERIORTHE MOST COMMON POSITION IS left mento anterior AS RIGHT OCCIPITO POSTERIOR IS 5 TIMES MORE COMMON THAN LEFT OCCIPITO POSTERIOR
MENTO ANTERIOR
MENTOPOSTERIOR
LEFTRIGHT
INCIDENCE: 1 IN 500 BIRTHS
Primary- during pregnancy Secondary- onset of labor
Fetal : 1.congenital malformations a) anencephaly b) goitre c) dolichocephalic
head d) bronchocoele2.Twist of cord round the
neck3.Hypertonicity of extensor
group of neck muscles
Maternal:1. Multiparity with
pendulous abdomen2. Lateral obliquity of
uterus3. Contracted pelvis4. Flat pelvis5. Pelvic tumours
ETIOLOGY:
PRODUCTION OF FACE PRESENTATION BY LATERAL
OBLIQUITY OF UTERUS PRODUCTION OF FACE PRESENTATION IN FLAT
PELVIS
MECHANISM OF LABOUR
THE PRINCIPLE DIFFERENCES BETWEEN OCCIPITOANTERIOR AND MENTOANTERIOR ARE:
OCCIPITO ANTERIOR
MENTO ANTERIOR
Engagement Engagement
Descent Descent
Flexion Extension Internal rotation Internal rotation
Extension Flexion Restitution Restitution
External rotation External rotation
Expulsion by lateral flexion Expulsion by lateral flexion
ENGAGEMENT Diameter of engagement: OBLIQUE DIAMETER
Right in LMA LEFT IN RMA
MENTUM One pubic eminence
GLABELLA Opposite sacro iliac joint
ENAGAGING DIAMETER is SUBMENTOBREGMATIC-9.5CM
Engagement is delayed because of long distance between mentum and biparietal plane i.e. 7cm where as to that of occiput is 3cm
DESCENT: with increasing extension descent occurs till chin touches the pelvic floor
Further descent occurs till submentum hinges under the pubic arch
INTERNAL ROTATION: occurs through 1/8th of the circle anteriorly placing mentum bheind the pubic symphysis
DELIVERY OF HEAD HEAD IS BORN BY
Diameter distending the vulval outlet is submentovertical-11.5cm
RESTITUTION: occurs through 1/8th of circle Opposite to direction of internal rotation
EXTERNAL ROTATION: occurs further 1/8th of the circle to the same side of restitution so that face looks
left thigh right thigh in LMA In RMA
FLEXION
•CHIN•FACE•BROW•VERTEX•OCCIPUT•ANTERIOR•SHOULDER•POSTERIOR•SHOULDER•TRUNK BY•LATERAL •FLEXION
DELIVERING
MENTOPOSTERIOR: 20-25% RMP OR LMP The principle differences between
occipitoposterior and mentoposterior are
20-30%cases -anterior rotation of mentum occurs
70-80% cases
INCOMPLETE
ANTERIOR ROTATION
NON ROTATION
SHORT POSTERIOR ROTATION
ANTERIOR ROTATION OF THE FETUS FROM RIGHT MENTOPOSTERIOR POSITION
Arrest occurs in all these positions with average size pelvis and foetal head
In short posterior rotation delivery there is no possibility of spontaneous delivery in mento posterior because
short neck cannot clear off the total length of the sacrum i.e.12cm
As such thorax is thrust in resulting BREGAMTICO STERNAL DIAMETER-18CM to occupy the pelvis as a result labour is obstructed
18CMS