Normal Labour and Puerperium Flashcards
What is the definition of labour?
Physiological process during which the foetus, membranes, umbilical cord and placenta are expelled from the uterus
Assoc with regular, painful uterine contractions with increased frequency, intensity and duration
What are the 3 birth options?
Consultant led unit
Midwife led unit
Homebirth
What is a birth plan?
Record of what the women would like to happen during her labour and afterbirth
What hormonal changes are thought to initiate labour?
Change in oestrogen/ progesterone ratio
Foetal adrenals and pituitary hormones
Myometrial stretch increases excitability of myometrial fibres
Mechanical stretch of cervix and stripping of foetal membranes
What is ferguson’s reflex?
Neuroendocrine reflex comprising the self-sustaining cycle of uterine contractions initiated by pressure at the cervix or vaginal walls
What is the role of progesterone in labour?
None; the reduction in progesterone initiates labour
Progesterone will keep the uterus settles, prevent the formation of gap junctions and hinders the contractibility of myocytes
What is the role of oestrogen in labour?
Uterine contraction
Promotes prostaglandin production
What is the role of oxytocin in labour?
Initiates and sustains contractions
Acts on decidual tissue to promote prostaglandin release
Synthesized directly in decidual and extraembryonic foetal tissues
Number of oxytocin receptors increases in myometrial and decidual tissues near end of pregnancy
What is the role of pulmonary surfactant in labour initiation?
Pulmonary surfactant in amniotic fluid stimulates prostaglandin synthesis
What is the role of foetal cortisol in labour initiation?
Increases maternal oestriol
What is the role of increased myometrial oxytocin receptors in labour initiation?
Increased phospholipase C activity and subsequently increase in calcium and uterine contractility
When can membranes rupture?
Pre-term Pre-labour First stage Second stage Born in caul
What makes up cervical tissue
Collagen tissue (1,2,3,4), smooth muscle, elastin, held together by connective tissue ground subtance
What are the factors that lead to cervical softening?
Increase in hyaluronic acid gives increase in molecules along collagen fibres
Decrease in bridging among collagen fibres gives decrease in firmness of cervix
What isi cervical ripening?
Decrease in collagen fibre alignment
Decrease in collagen fibre strength
Decrease in tensile strength of cervical matrix
Increase in cervical decorin
What are the 5 elements of bishops score?
Position Consistency Effacement Dilatation Station in pelvis
What is the bishop’s score used for?
Safe to induce labour
What does a score of less than 5 on the bishop’s score indicate?
Candidate for cervical ripening prior to induction
What are the 2 phases of 1st stage of labour?
Latent and active
Latent; mild, irregular contractions, cervix shortens and softens, duration variable
Active phase; 4cm to full dilatation. Slow descent of presenting part. Contractions become rhythmic and strong.
What is normal progress in the active stage of 1st stage of labour?
1-2cm per hour
What is the 2nd stage of labour?
10cm to delivery of baby
What is a normal length for 2nd stage of labour in a nulliparous woman?
Prolonged if over 2 hours
Prolonged if over 3 hours with regional analgesia
What is a normal length for 2nd stage of labour in a multiparous woman?
Prolonged if over 1hr
Prolonged if over 2hr with regional analgesia
Should vaginal examinations be carried out in low risk women who are fully dilated?
No; high risk of introduction of infection
What is the 3rd stage of labour?
Delivery of baby to expulsion of placenta and foetal membranes
What is the average duration of 3rd stage of labour?
10 mins
What will occur after 1hr of 3rd stage?
Removal under GA
What is active management of 3rd stage?
Use of oxytocic drugs and controlled cord traction
Preferred for lowering risk of PPH
What are braxton hicks contractions?
“False labour”
Tightening of uterine muscles, to aid body for birth
Irregular, do not increase in frequency or intensity
Resolve with ambulation or change in activity
When can braxton hicks start?
6 weeks into pregnancy
Much more likely to be 3rd trim
More likely in multiparous women
What is true labour?
Timing of contractions becomes evenly spaces, and time between them gets shorter with the length of contractions increasing
What are the 3 key factors to labour?
Power; uterine contractions
Passage; maternal pelvis
Passenger; foetus
Where will contractions start and how will they spread?
Pacemaker is in the tubal ostia
Wave spreads symmetrically in a wave down the uterus
What is polarity of uterine contractions?
Upper segment contracts and retracts
Lower segment and cervix stretch, dilate and relax
What is normal and sufficient contractions in active labour?
3-4 every 10 mins
Initially 10-15 secs to a max of 4 secs
Intensity; degree of uterine systole
What is an anthropoid pelvis?
Oval shaped inlet with large AP diameter and comparatively smaller transverse diameter
What is an android pelvis?
Triangular or heart shaped inlet with a narrower front
What is the most suitable pelvic shape for labour?
Gynaecoid
What impact will anthropoid and android pelvices have on labour respectively?
Anthropoid; long 2nd stage
Android; long 1st stage
How is thee cervix assessed in labour to determine passage?
Effacement Dilatation Firmness Position Station
What is the normal position of the foetus?
Longitudinal lie
Cephalic presentation with the vertex presenting
OA, head engages occipito transverse
Flexed head
What are abnormal presentations and positions of the foetus?
Presentation; breech, oblique, transverse lie
Position; occipito posterior
How can the position of the foetus be determined on vaginal exam?
Fontanelles
Anterior; diamond shaped with 4 sutures coming off
Posterior; triangular with 3 sutures
What are the analgesia option for birth?
Paracetamol TENS Entonox Diamorphine Epidural Combined spinal/ epidural
What is a partogram?
Graphic record of key data contained on one sheet, used to assess the progress of labour i.e. cervical dilation, foetal heart rate
What are the 7 cardinal movements of labour?
Engagement Descent Flexion Internal rotation Crowning and extension Restitution and external rotation Expulsion
What is engagement?
Passage of occipitofrontal diameter transversely past pelvic inlet
What is descent?
Downward passage of presenting part through pelvis
How is engagement described in terms of fifths?
3 fifths with engaged
What needs to be observed in decent of the foetus?
Abdominal fifths
Maternal discomfort and feeling of pressure
Frontal synciput and occiput eminences
Vaginal examination for cervical assessment
What is flexion of the foetal head in labour?
Occurs passively as the head descends due to shape of bony pelvis and resistance of soft tissues
What is internal rotation of the foetal head in labour?
Rotation of presenting part from transverse position to AP position to allow passage through pelvic outlet
What is extension of the foetal head in labour?
Occurs once the foetus has reached level of introitus, bringing the base of the occiput in contact to the inferior margin at the symphysis pubis
What is external rotation (restitution) of the foetus in labour?
Return of foetal head to correct anatomical position in relation to foetal torso
What is the role of external rotation?
Allows delivery of shoulder; anterior shoulder first
What is crowning?
Appearance of large segment of foetal head at introitus
Labia are stretched to full capacity
Largest diameter of foetal head is encircles by vulvar ring
Why should delivery of head by managed carefully?
Prevent rapid extension and perineal tearing
What is the rationale behind delayed cord clamping?
Higher red blood cell flow to vital organs in first week, less anaemia, increased duration of breastfeeding
Higher infant haematocrit, Hb levels, BP, BV
Improved cardiopulmonary adaptation
When will delayed cord clamping not be performed?
If immediate resuscitation is required
Why is immediate skin to skin recommended?
Keeps babies warm
Improve babies transition to life outside womb
Increased breastfeeding
What is the current recommendation regarding skin to skin after birth?
Uninterrupted SSC for 1 hour following birth
What are the 3 classical signs of separation of placenta?
Uterus contracts, hardens and rises
Umbilical cord lengthens permanent
Gush of blood
Placenta and membranes appear at introitus
What is included in active management of the 3rd stage of labour?
Prophylactic administration of syntometrine and oxytocin OR just oxytocin Cord clamping and cutting Controlled cord traction Bladder emptying
What is the plane of separation for the placenta?
Spongy layer of decidua basalis
What is the most common method of separation?
Matthew duncan; detachment of the leading edge of the placenta, and the entire organ slips down and out of the uterus sideways
What is the schultz method of separation?
Separation begins in the center of the placenta (the fetal surface), and this part descends first, with the remainder following
What is a normal amount of blood loss post birth?
Less than 500ml
How is haemostasis achieved in the postpartum period?
Tonic contraction; lattice pattern of uterine muscles strangulates blood vessels
Thrombosis of torn vessels; pregnancy is a hypercoagulable state
Myo-tamponade-opposition of AP walls
What is lochia?
Vaginal discharge containing blood, mucus and endometrial castings
Describe the vaginal discharge in the puerperium stage?
Rubra; fresh red; 3-4 days
Serosa; brown/ red, watery; 4-14 days
Alba; yellow; 10-20 days
At what time will the tissues be returned to the non-pregnant state?
6 weeks
When will the fundal height return to normal post birth?
Umbilicus to within pelvis by 2 weeks
When will the endometrium regenerate post birth?
By the end of the week; except the placental site
What areas of the reproductive system of women will never return to pre-pregnancy state?
Cervix
Vagina
Perineum
When will physiological diuresis occur post birth?
2-3 days
What is lactation initiated by?
Placental expulsion
Decrease in oestrogen and progesterone
Why is milk not produced in pregnancy?
Oestrogen and progesterone act negatively on pituitary gland to prevent prolactin release
Render mammary glands unresponsive to prolactin
What is colostrum rich in?
Immunoglobulin; has long term protective effect for baby
