Normal Labour and Peurperium Flashcards
What is labour?
A physiological process during which the fetus, membranes, umbilical cord and placenta are expelled from the uterus
What are the features of labour?
Regular, painful uterine contractions with increasing frequency, intensity and duration and accompanied biochemical changes in the cervical tissue allowing cervical effacement and cervical dilatation.
What are the 3 main factors for labour?
Power - uterine contractions
Passage - Maternal pelvis
Passenger - Fetus
In labour, what is the role of progesterone?
Keeps the uterus settled
Prevents formation of gap junctions
Hinders the contractibility of myocytes
In labour, what is the role of Estrogen?
Makes the uterus contract
Promotes prostaglandin production
In labour, what is the role of Oxytocin?
Initiates and sustains contractions
Acts on decidual tissue to promote prostaglandin release
Synthesised directly in decidual and extraembryonic fetal tissues and in the placenta
When does the number of oxytocin receptors increase?
In myometrial and decidual tissues near the end of the pregnancy
What Initiates labour?
Change in estrogen/progesterone ratio
Fetal adrenals and pituitary hormones may control the timing of onseet of labour
Myometrial stretch increases excitability of myometrial fibres
Mechanical stretch of cervix and stripping of fetal membranes
Fergusons reflex
What has been known to stimulate prostaglandin synthesis?
Pulmonary surfactant secreted into amniotic fluid
What happens in the 1st stage of labour?
Latent ohase up to 3-4cm dilation
Active stage 4cm - 10cm (full dilation)
Cervix shortens and softens, may be an uncomfortable few days
What happens in the 2nd stage of labour?
Full dilation - delivery of baby
Give analgesia
What happens in the 3rd stage of labour?
Baby is delivered
Expulsion of placenta and membranes
What active management is done to lower the risk of post partum haemorrhage?
Oxytocic drugs
Controlled cord traction
What else can be given in the 3rd stage of labour?
Prophylactic administration of syntometerine
1ml ampoule containing 500 micrograms ergometrine maleate and 5IU oxytocin
What causes an increase in molecules among collagen fibres?
Increase in hyaluronic acid
What causes cervical ripening?
Decrease in collagen fibre alignment
Decrease in collagen fibre strength
Decrease in tensile strength of the cervical matrix
Increase in cervical decorin (Dermatan sulphate proteoglycan 2)
What are Braxton Hicks contractions?
Tightening of the uterine muscles, thought to aid the body prepare for birth
When can Braxton Hicks start?
6 weeks into the pregnancy
Not usually felt till 2nd or 3rd trimester
How far apart do true contractions start?
5 mins
How will the abdomen feel during a contraction?
Hard
How does a contraction pain manifest itself?
Starts low and rises until it peaks and ebbs away
How do Braxton Hicks contractions manifest themselves?
Irregular, don’t increase in frequency or intensity
Resolve with ambulation or change in activity
Relatively painless
What are characteristics of Uterine contractions?
Smooth muscle (myocyte) in connective tissue (collagen and elastin). Density highest at fundus
What are the characteristics of Cervical tissue?
Collagen tissue mainly (type 1,2,3,4) smooth muscle, elastin, held together by connective tissue ground substance
What does contractions and retraction lead to?
Shortening of the muscle fibres
What controls the contractions’ power?
Pacemaker is the region of tubal ostia - wave spreads in a downward direction
What causes polarity of the contractions?
Upper segment contracts and retracts, lower segment and cervix stretch, dilate and relax
Describe the Anthropoid pelvis
There’s an oval shaped inlet with large anterio-posterior diameter and comparatively smaller transverse diameter
Describe the Android pelvis
Has triangular or heart shaped inlet and is narrower from the front. African-Caribbean women are more at risk of having an android shaped pelvis
What is the normal fetal lie?
Longitudinal lie
Cephalic presentation
What is the normal position?
Occipito-anterior; head engages occipito-transverse
Flexed head
What is an abnormal presentation?
Breech
Oblique
Transverse lie
Position - Occipito-posterior
What is crowning?
Appearance of a large segment of fetal head at the introitus
What happens to the labia during crowning?
Stretched to full capacity
What can be down to prevent trauma to the anal spinchter and the pudendal nerve?
Episiotomy
What are the 5 elements of the Bishops score?
Position Consistency Effacement Dilatation Station in pelvis
What is the Bishops score used for?
To see whether or not it is safe to induce labour
What are options for analgesia?
Paracetamol/Co-codamol TENS Entonox Diamorphine Epidural Remientanyl Combined spinal/epidural
What volume of blood loss during pregnancy would be classed as abnormal?
Over 500mls
When is blood loss during pregnancy classed as significant?
Over 1,500mls
What should be done if a female loses blood prior to delivery?
Refer to a consultant unit
What is the plane of placental separation?
Spongy layer of decidua basalis
What is a Schultz separation?
Separation from the central aspect
What is a Matthew Duncan separation?
Marginal separation - most common
What 3 things can give rise to Haemostasis?
Tonic contraction: Lattice pattern of uterine muscle strangulates the blood vessels
Thrombosis of the torn vessel ends: Pregnancy is a hyper-coaguable state
Myo-tamponade-opposition of the anterior/posterior walls
What is Puerperium?
Period of repair and recovery
Return of tissues non-pregnant state
What is Lochia?
Vaginal discharge containing blood, mucus and endometrial castings
What is Rubra?
Fresh red
What is Serosa?
Brownish-red, watery
What is Alba?
Yellow
How long does it take for the endometrium to regenerate?
1 week
How long does it take for the fundal height to return?
2 weeks
When does Diuresis occur?
2-3 days postnatally
What initiates lactation?
Placental expulsion
Decreased oestrogen
Decreased progesterone
Prolactin is maintained
What is colostrum rich in?
Immunoglobulin
