Normal Labour and Peurperium Flashcards
What is the second stage of labour
From full dilatation to delivery of baby
What is the third stage
Delivery of baby to expulsion of placenta
Name the factors that contribute to the initiation of labour
Change in oestrogen/progesterone ratio
Fetal adrenals and pituitary hormones
Stretch fibres in myometrium and cervix
Fergusons reflex
What is Fergusons reflex
Pressure on the cervix results in a release of oxytocin which increases contractility. The increases contractions acts as positive feedback on the pituitary resulting in more oxytocin release.
Role of progesterone in labour
Inhibits formation of gap junctions and therefore reduces contractility of the uterus
Role of oestrogen in labour
Makes uterus contract and promotes prostaglandin production
Describe the role of oxytocin in labour
Initiates and sustains contractions
Promotes prostaglandin production
What defines the start of labour
Regular contractions which increase in strength and frequency and bring about cervical change.
The show and rupture of membranes does not define the start of labour
What is effacement
Process by which the cervix shortens in length as it be c ones included into the lower segment of the uterus
When is the second stage of labour considered prolonged in a nulliparous woman
If more than 3hrs with regional anaesthesia
If more than 2hrs without
When is the second stage of labour considered prolonged ina multiparous woman
If more than 2hrs with RA
If more than 1hr without RA
What is the average duration of the third stage of labour
About the minutes but can be up to thirty minutes
After one hour the placenta needs to be removed under GA
Why would active management of the third stage be preferable to expectant
Decrease risk of PPH because oxytocin is injected into cord and ergometrine administered
What is the most suitable type of pelvis for labour
Gnaecoid
Which pelvis shape is heart shaped and common in tall or Afro Caribbean women
Android
What type of pelvis is wider in the AP direction
Anthropoid
What is the normal feral position
Cephalic lying longitudinally. Vertex is occipital anterior.
Where does placental separation occur
The deciduous basal is at the spongy layer
What are the three classic signs of the third stage of labour
Uterus hardens and contracts and rises
Umbilical cord lengthens
Gush of blood
How long does it take for. Tissues to return to normal after puerperium
About 6 weeks
What is the first stage of labour
Latent + active phase
Up to 3-4cm dilation = latent
4-10cm = active
What is lochia
Vaginal discharge after birth - may contain blood mucus and endometrium
What are the various colours of lochia
Rubra (red)
Serosa (brown)
Alba (yellow)
How long does it take for the endometrium to regenerate after birth
About 1 week
How long does it take for the fundal height to reduce and the umbilicas to be in the pelvis
Within 2 weeks
What initiates lactation
Placental expulsion
Decrease in progesterone and oestrogen
Prolactin maintained
What is the definition of engagement
When the widest part of the presenting part has passed through the pelvic inlet and is less than 2/5 palpable in the abdomen
Which Fontannelle is larger
Anterior
Where is oxytocin synthesised
Directly in the decidual and extraembryonic fetal tissue and in the placenta
What happens to the number of oxytocin receptors in the myometrial and decidual tissues near the end of pregnancy
Increase
What other factors may contribute to the initiation of labour
Pulmonary surfactant secreted into amniotic fluid stimulates prostaglandin release
Fetal cortisol rises stimulating maternal estriol
Increase in myometrial oxytocin receptors results in increase in calcium and uterine contractility
How long may the latent phase of labour last
Can last days
What causes cervical softening
Increase in hyaluronic acid results in increased molecules among collagen fibres decreasing the bridging of these fibres and softening the cervix
What causes cervical ripening
Decrease in collagen fibre alignment, strength
Increase in cervical decorin
Decreases in strength of cervical matrix
What is the pacemaker for contractions
Tubal ostia
How often in the cervix assessed in normal labour
Approx four hourly
What is bishops score used for
To asses whether induction of labour is required
At why bishops score is it likely that labour will not start without induction
Five or less
At what bishops score is it unlikely that induction will be very successful
Less than 8
What are the five aspects of the bishops score
Position Consistency Effacement Dilatation Station in pelvis
Dilatation
0cm = 0
1-2cm = 1
3-4cm = 2
5 or more = 3
Effacement
0-30%= 0
40-50%= 1
60-70%= 2
80-100%=3
Station
-3=0
-2=1
-1=2
+1 or +2=3
Consistency
Firm = 0 Med = 1 Soft= 2
Position
Posterior 0
Mid 1
Anterior 2
What are the analgesic options in pregnancy
Paracetamol TENS Entonox Diamond phone Epidural Remfentanyl Spinal or epidural
What blood loss in labour would be abnormal
Any volume greater than 500ml
Any blood loss prior to delivery apart fro the show
