Normal labour Flashcards
What is labour?
Process of birth
Includes the expulsion of fetus and the placenta
3 stages of unequal length
What are the three stages of labour?
First stage: onset of labour - cervix fully dilated
Second stage: full dilation - delivery of baby
Third stage: Expulsion of placenta and membranes
Describe the first stage of labour
Contractions - cervix fully efaced
Cervical dilation
Describe the second stage of labour
Propulsive: full dilation with head to pelvic floor
Expulsive: irresistable desire to bear down/push = delivery
Describe the third stage of labour
Cord lengthens
Gush of blood
Fundus of uterus rises
Controlled cord traction
Describe the mechanism of normal labour
Head at pelvic brim in left occipito lateral position
Neck flexes and presenting diameter is suboccipito bregmatic
Head hits pelvic floor - Occiput rotates => Occipito anterior
Head delivers by extension
Head restitutes (comes in line with shoulders)
Descent continues and shoulders rotate into the AP diameter of the pelvis
Anterior shoulder slips under pubis and with lateral flexion baby is born
What is normal labour characterised by?
Regular painful uterine contractions
Dilation of cervix
Descent of head
What are some of the other associates symptoms with labour?
A “show” (operculum) = a blood stained mucus discharge
- 2/3 of women by onset of labour
Spontaneous rupture of membranes
- 1/3 of at onset of labour
What are the cardinal signs of labour during the process of birth?
Effacement
Dilation of cervix (external orifice of the uterus)
What is a primigravid labour and what are the risks?
First labour
- inefficient uterine action
- risk of cephalopelvic disproportion/foetal trauma (rare)
- rupture of uterus (never happens)
What is a multigravid labour and what are the risks?
Not first labour
- Risk of uterine rupture
Define caput
Oedema at the head
- due to pressure against rim of the cervix
Define moulding
Overlapping of the vault bones
- shape of the skull bones alter so that the diameters shorten
Define engagement
Descent of biparietal diameter through pelvic brim
Define the lie of a foetus
Relation of long axis of foetus to mother’s vertebral column
Define presentation
The part of the foetus that is in the lower pole of uterus
Define attitute
The posture of the foetus
- flexion
- deflexion
- extension
Normal attitude is flexion when presentation is vertex
Define position
The relationship of the presenting part to the mother’s pelvis
- e.g. left occiput anterior
The denominator is the abitrary part of presentation
- occiput in vertex presentation
- sacrum in breech presentation
- mentum in face presentation
When is the head engaged?
When head at level of ischial spines (unless of caput)
<= 2/5 palpable per abdomen
What is cephalic presentation?
When the head is first foetal part in lower pole of uterus
i.e. vertex, sinciput, brow, face, chin
What is breech presentation?
The opposite to a cephalic presentation
i.e. complete, footling, frank
What is shoulder presentation?
Presentation of arm, shoulder, trunk first
What is the station?
The relationship of the head to ischial spines
- ischial spines: station = 0
Above ischial spine => station -1, -2, …, -4cm
Below ischial spine => station +1, +2, …, +4cm
What is syntocinon and what is it’s funtion?
Synthetic oxytocin
- an octapeptide that causes rhythmic uterine contraction
Acts within 2 mins when given IV
