Normal labour Flashcards
Stage 1 of labour?
= onset until cervix is fully dilated
Latent stage of labour
Part of stage 1
Onset until cervix = 4 cm dilated
Involves effacement of the cervix (internal Os is incorporated into the uterus)
In PG
Active stage of labour
Part off stage 1
4 cm until fully dilated
Should dilate at 1.2 cm/hr in PG and 1.5 cm/hr in MG
Stage 2
Full dilation until delivery
should last
Propulsive phase
Stage 2a
Baby propelled by uterine contractions
Full dilation till the head hits the pelvic floor
Expulsive phase
Stage 2b
Baby expelled by pelvic floor muscles
Irresistible urge to push (caused by floor stretching) till delivery
Stage 3
The afterbirth
Expulsion of placenta and membranes
Operculum?
a.k.a a show
Blood stained mucus discharge, occurs in 2/3rd during early stages of labour as there is a discharge of a plug of mucous within the cervical canal
Engagement
Descent of the biparietal diameter through the pelvic brim, clinically defined as 2/5th or less palpable per abdomen
Lie
Relation of the long axis of the foetus to the mother
Longitudinal (normal)
Oblique
Transverse
Presentation
Part of the foetus in the lower pole of the uterus
Cephalic - head
Vertex - in transverse lie
Breech - bottom/feet
Position
Relationship of presenting part of baby to pelvis
LOL - left occipito lateral
DOA - direct occipito anterior (chin to chest)
DOP - direct occipito posterior (face to pubes)
If in breech then use sacrum instead of occipito
Attitude
Degree of flexion/extension of the foetal head
Station
Relation of head to the ischeal spines
-3 = 3cm above
0 = level
+4 = 4cm below and out
Oxytocin
Secreted by pituitary
Important for effacement and stimulation of uterine contraction
Syntocinon
Synthetic oxytocin
Used for inefficient uterine contraction - PG only, and in post partum haemorrhage (induces strong contractions to aid clotting)
When should syntocinon be used with caution?
Previous C-section - risk of rupture
If mother has a high BP as can increase it further
Ergometrine uses
Used in postpartum haemorrhage
Induces tetonic contraction - prolonged spasm
Lasts up to 30mins
Clamps down uterus to aid clotting
Cautions with Ergometrine
HIgh BP, can increase further
Syntometrine
Syntocinon + Ergometrine combined
Quick acting and longer lasting
Dinoprostone
Prostaglandin E2 Analogues
Ripens and effaces the cervix
Used to induce labour
Inserted vaginally
What are the 3 reasons for failure to progress?
The 3 Ps
1 - Powers = Pushing - forces generated by uterine contraction
2 - Passenger - foetal size, presentation, position, attitude
3 - Passage - bony pelvis size/shape and soft tissue resistance. Normally = gynecoid but can be platypoid, anthropoid, android
What are the common causes of failure to progress?
IUA - inefficient uterine contraction (PGs), give syntocinon
OP presentation ~10%
CPD - cephalo-pelvic disproportion ~1/250 births
Risk screening for Down’s syndrome
Triple test between 15-20wks tests hormone levels , maternal age and gestational age (NHS)
Nucchal Traslucency, 11-14 wks, inc NT suggests heart failure and chromosomal abnormalities
Integrated test, 11-14 wks = triple test + NT to increase sensitivity and specificity
