Mechanism of labour Flashcards
What is mechanism of labour for baby in Anterior position
Descent
flexion (enter brim transverse 11cm)
internal rotation (12cm)
crowning
extension (Anterior posterior diameter) - sinciput, face and chin sweep perineum
restitution (head returns to correct alignment with shoulders )
shoulders internally rotate (to fit AP diameter of outlet)
head externally rotates (head move stowards woman’s thigh)
shoulder released (usually anterior)
laternal flexion
describe the two fontanelles
what are they?
location / size / shape / when do they close
space / soft spots on head
where sutures join
anterior fontanelle (bregma)- smaller, diamond, closes last (8mths). Joins frontal + parietal bone
posterior fontanelle (lambda)- larger / triangle, closes first (2mths). Joins Occiput bone and parietal bone
what are sutures?
where are they?
elastic tissue that hold together bones of head - enabling spaces / moudability
Sagittal suture (along vertex)
coronal suture (coming off bregmatic fontanelle)
What are the sections of the head, in relation to fontanelles
occiput (under posterior fontanelle)
vertex (between anterior and posterior fontanelle)
Sinciput/ brow (between anterior fontanelle and Occipitofrontal diameter)
Glabella (between eye and nose)
face (sit under occipitofrontal diameter)
Mentum (chin)
where is glabella
skin between eyebrows and nose
what is definition of presentation
the part of the baby in the pelvic brim (cephalic/ breech / shoulder )
what is definition of presenting part (list for each presentation)
part of body that lies closest to cervix
(cephalic- vertex, brow, face)
(breech- (frank- legs extended), complete (feet tucked to bottom), footling)
what is definition of “lie”
relationship of mum’s back to baby
longittudinal
transverse
obligue
what is definition of attitude
Relationship of fetal head and limbs to its body
fully flexed / deflexed/ partially or completely extended
what is definition of denominater
landmark on presenting part, describes degree of rotation
vertex- occiput
buttock- sacrum
face- metum
what is definition of position
relationship between denominator (occiput / sacrum) nad pelvic brim (left / right / anterior / posterior)
Describe vertex presenting part
what is denominator
what are types of flexion and circumferences?
denominator- occiput
Fully flexed Vertex -Suboccipital bregmatic diameter (9.5)
partially deflexed- suboccipital frontal (10.5)
deflexed vertex- occipitalfrontal (11.5)
Describe face presentation
what is denominator
what are types of flexion and circumferences?
what position does menum need to be in, to birth
denominator- mentum
Extended- submentum bregmatic 9.5
partially extended- submentum vertical 10.5
mentum needs to be anterior (if posterior, it gets stuck at sacrum)
Describe brow presentation
what is denominator
what is diameter
denominator- glabella
mentovertical - 13.5cm
what is biparietal diameter?
diameter between parietal bones (cephalic presentation)
9.5cm
what is bisacral diameter
diameter between sacral bones (breech presentation)
9.5
What is OP position / signs on palpation + VE
definition-
baby’s occiput is posterior
back to back
Signs
spine felt at flank / not palpable
mum feels movements on both sides
dip under umbilicus
Posterior fontanelle (triangle) in bottom quadrant
may have irregular cx
mechanism of labour - OP (long rotation)
Station
Definition and classification
Relationship to presenting part and ischial spines
+1 = going past spines (below spines)
-1 = above spines
Descent
Definition and how to classify
How much of baby’s head is palpable (above brim)
5/5 = all palpable
0/5 = not in brim at all
what are 3 scenarios for baby in posterior position in labour
long rotation
- flexed head can rotate full 135 degrees to get into anterior position
short rotation
- head is deflexed, so can’t rotate fully. completes short rotation and born face to pubes (12.5cm - occipito mento)
deep transverse arrest-
head attempts long rotation but arrests at level of spines
What is bracht manouvre
indication
indication- continued progree
‘hands off’!
Louwen manouvre
indication
what does it involve
when
descent halts before nipple line, and body is SACRO OBLIQUE ( instead of sacro anterior)
manouvre
mum’s hands circle mody
turn baby 180 towards direction it came, then back 90
then wait
LOVSET Manouvre
indication
manouvre:
indication
progress halts at umbilicus - due to upward displacement of arms (e.g. shoulder caught under pubic symphysis)
manouvre
lift body anteriorly (= lateral flexion)
rotate trunk 180 (keeping back anterior)- release posterior shoulder
repeat - rotate trunk reversely 190 degrees, to release anterior shoulder)
leave baby to hang
kristerllir manouvre
indication
manouvre
progress halts at umbilicus- arms out
manouvre- apply suprapubic pressure to maintain occipital flexion
mauriceau smellie manouvre
indication
indication- progress halts at umbilicus
manouvre-
fingers pressing down on chin
other hand- push down on back, finger pushing down on occiput ot keep flexion
shoulder press
indication- head not releasing, as it’s not flexed
press down on shouders
can also do rock and roll
Describe 3 Types of Breech presentating parts
frank- legs extended, pelvis flexed. presenting part is buttocks.
complete- pelvis and knees flexed. presnting part is buttocks (feet are near buttocks)
incomplete- either 1 or both hips + knees flexed= either feet or knee is below hte buttock.
if mentum is denominator, what is presentation
face
