Normal Labour and Puerperium Flashcards
what is puerperium
6 weeks after childbirth
what is expelled from the uterus in labour
fetus, membranes, umbilical cord and placenta
what is cervical effacement
thinning of the cervix during labour
what happens to contractions as labour progresses
become more frequent, intense and last longer
what causes the initiation of labour
unknown:
change in oestrogen/ progesterone ratio (oestrogen increases)
fetal adrenal and pituitary hormones may have an impact
myometrium stretch increases excitability of myometrial fibres
mechanical stretch of cervix
stripping of fetal membranes - baby pushes more on cervix
fergusons reflex- positive feedback system, pushing down on cervix causes more contractions and dilatation
pulmonary surfactant when secreted into amniotic fluid stimulates prostaglandin synthesis
increase in fetal cortisol -> increases maternal estriol
increases in myometrial oxytocin receptors + their activation = phospholipase C activity = increased cytosolitic calcium and uterine contractility
what is the role of progesterone in labour
(prevents it)
keep uterus settled
prevents the formation of gap junctions
hinders the contractibility of gap junctions
what is the role of oestrogen in labour
makes the uterus contract
promotes prostaglandin production
what is the role of oxytocin in labour
initiates and sustains contractions
acts on decidual (endometrial) tissue to promote prostaglandin release
where is oxytocin produced
decidual tissue
extraembryonic fetal tissues
placenta
what happens to oxytocin receptors in the myometrium and decidual tissues in pregnancy
numbers increase towards the end of pregnancy
what is the role or liquor
nutures and protects the fetus and facilitates movement
what doe it mean to be born in a caul
when membranes dont rupture and babies born inside them
what makes up cervical tissue
collagen tissue mainly (types 1-4), smooth muscle, elastin
held together by connective tissue ground substance
what causes cervical softening
increase in hyaluronic acid decreases bridging among the collagen fibres= decrease in the firmness of the cervix
what causes cervical ripening
decrease in collagen fibre strength and alignment
decrease in tensile strength of the cervical matrix
increase in cervical decorin
what does the bishops score determine
whether it is safe to initiate labour
what does the bishops score quantify
dilatation effacement station cervical consistency (firm, med, soft) cervix position (post, mid, anterior)
higher the score more likely/ safer to go into labour
lower score need cervical priming and induction
what are the stages of labour
1st stage:
- latent (0-3cm)
- active (4cm-7cm)
- transition (8-10cm)
2nd- from complete dilation and effacement to delivery
of baby
3rd- from delivery of baby to delivery of placenta
what happens in the latent phase of labour
mild irregular contractions
cervix shortens and softens
duration is variable- can last several days
what happens during the active first phase of labour
from 4cm to full dilatation
slow descent of the presenting part
contracting become more rhythmic and stronger
normal progress= 1-2cm dilation per hour
when is the 2nd stage of labour considered prolonged
nulliparous- when exceed 2 hours or 3 hours if regional anaesthesia
multiparous- if exceeds 1 hour or 2 hours with regional anaesthesia
are vaginal exams always done in the 2nd stage of labour
not if fully dilated in low risk pregnancies as associated with infections
what happens in the third stage of labour
delivery of baby
expulsion of placenta and fetal membranes
how long does the 3rd stage of labour usually last
average 10 mins
if longer than an hour emergency CS
what are the different managements for the delivery of the 3rd stage of labour
spontaneous delivery active management- oxytocic drugs: prophylactic administration of Syntometerine (1ml ampoule containing 500 micrograms ergometrine maleate and 5IU oxytocin) OR Oxytocin 10 units Cord clamping and cutting, Controlled cord traction Bladder emptying
what do oxytocic drugs and controlled cord traction lower the risk of
post partum haemorrhage
what are braxton hicks contractions
aka false labour
tightening of uterine muscles (aids body for birth)
can start 6 weeks into pregnancy, usually happen in 3rd trim
irregular, do not increase in frequency or intensity
resolve with movement/ change in activity
relatively painless
what hormone causes true labour contractions
oxytocin- stimulates the uterus to contract
what are true labour contractions like
timing = evenly spaces, time between gets shorter
length of contraction increases usually from 10 -> 45 seconds
get more painful
starts in fundus and spreads downwards
what is the role of contractions
tightens to top part of uterus pushing baby downward into canal to prepare for delivery
promotes the thinning of the cervix
where is the uterus highest in density of smooth muscle
at the fundus
what is the pacemaker of the uterus
region of the tubal ostia
wave of contraction spreads downwards from here
synchronisation of contraction waves from both ostia
what happens to either end of the uterus during contractions
upper segment contracts and retracts lower segment (and uterus) stretch, dilate and relax
how many contractions is it normal to have in 10 mins
3-4
is resting tone between contraction important
yes
when are contractions at their maximum
in 2nd stage of labour
what are the types of female pelvis
anthropoid- oval shaped, large AP diameter, smaller transverse diameter
android- triangular/ heart shaped inlet, narrower at the front, more common in african caribbean women
gynaecoid pelvis- most suitable for child birth
what is the cervix assessed for in labour
effacement dilatation firmness position level of presenting part/ station
what is the normal fetal position in labour
longitudinal lie cephalic presentation (vertex is presenting part) occipito-anterior, flexed
what is an abnormal fetal presentation
breech, oblique or transverse lie
occipito- posterior
what are the fetal positions within the pelvis (cephalic presentation)
right and left occipito posterior
right and left occipito anterior
what can be felt on vaginal exam to determine the position of the fetus in pelvis
fontanelles
what are the analgesic options of birth
paracetamol/ co-codamol (taken in initial stages)
TENS
entonox
diamorphine (1st line for when too sore for paracetamol)
epidural
remifentanyl
combined spinal/ epidural
what is recorded in a partogram
- fetal HR and how it is monitored (continuous electronic, intermittent, fetal scalp electrode, handheld doppler, pinard stethescope)
- fetal pH
- liquor
- caput/ moulding
- position
- cervical dilatation
- descent of presenting part
- contractions per 10 mins
- duration of contractions
- time
- syntocinon given?
- epidural given?
- medications given
- maternal BP
- maternal pulse
- maternal urinalysis
what are the cardinal movements of the babies head in the fetus
engagement (passage of widest part into plevic inlet, 3/5ths of head in pelvis, 2/5ths abdominal)
decent (through pelvis, in occipito transverse position)
flexion (passive movement)
internal rotation (of presenting part from -usually- transverse to anterior position)
crowning and extension (occiput in contact with inferior margin of symphysis pubis)
restitution (aka external rotation) (optimal position for shoulder)
expulsion (anterior shoulder first)
how often should vaginal exams be done in normal labour
every 4 hours
what happens at crowning
Appearance of a large segment of fetal head at the introitus
Labia are stretched to full capacity
Largest diameter of fetal head is encircled by the vulval ring
Burning and stinging feeling for the mother
when should the umbilical cord be clamped
should be delayed- after pulsations have stops/ 3 mins after birth
unless immediate resuscitation is necessary
how long skin to skin time after birth
1 hour uniterrupted following birth
when is the placenta usually delivered
5-10 mins after birth
considered normal after 30 mins
what are the signs that indicate a separation of the uterus
Uterus contracts, hardens and rises
Umbilical cord lengthens permanently
Frequently a gush of blood variable in amount
Placenta and membranes appear at introitus
what layer is separated when the placenta is delivered
the spongy layer of decidua basalis
what is the mechanism of placental separation
Shearing force
Inelastic placenta reduces surface area on the placental bed due to the sustained contraction of the uterus
what is a normal amount of blood loss in childbirth
less than 500ml
when is blood loss in childbirth significant
when >1000ml
how is haemostasis achieved in labour (to prevent blood loss)
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.
how long till tissues return to non pregnant state
6 weeks
what is lochia and what are the different forms
Vaginal discharge containing blood, mucus and endometrial castings
Rubra (fresh red) 3-4 days after birth
Serosa (brownish-red, watery) 4-14 days
Alba (yellow) 10-20 days
Bloodstained discharge lasts for about 10-14 days following birth
what uterine changes occur in the puerperuim
involution
Weight -1000gms reduces to–50-100gms
Fundal height –umbilicus to within pelvis in 2 weeks
Endometrium regenerates by end of a week (except the placental site)
Regression but never back to pre-pregnancy state; cervix, vagina and perineum
Physiological diuresis commences 2-3 days postnatally
what initiates lactation
placental expulsion and a decrease in oestrogen and progesterone
increase in prolactin
what is colostrum rich in
immunoglobulins
what are the indications for induction of labour
maternal:
- pre eclampsia
- poor obstetric Hx
- medical disorders
fetal:
- susoected IUGR
- rhesus isoummunisation
- antepartum haemorrhage
- PROM
post dates pregnancy
diabetes mellitus
obstetric cholestasis
what are the mechanisms of induction of labour
Prostaglandins - PGE2 Dinoprostone (Prostin gel / Propess pessary)
Mechanical: Membrane sweep, Foley Balloon Catheter
Amniotomy
IVI Syntocinon
what is the action of diamorphine
opiate mu receptor agonists in peri aqueduct grey matter, blocks pain signals
what are common SEs of diamorphine
arrhythmias confusion constipation dizziness drowsiness dry mouth euphoric mood flushing hallucinations HA hypotension miosis nausea and vomiting (more common in first dose) resp depression pruritis urinary retention bradycardia
how can a fetus be affected by diamorphine
resp depression
withdrawal symptoms
gastric stasis
inhalation pneumonia
what is an epidural
bupivacaine and fentanyl into epidural space, regional anaesthetic
what nerves does an epidural block
from T10-12 downwards (uterus supplied by t10-12, vagina S2,3,4)
what special precautions should be taken with epidural anaesthesia
before doing it get IV access for fluids- hypotension a SE, risk of fetal distress
loose bladder control- catheterise
loss of power in legs (when light can move but loose proprioception, when heavy cant move legs (forceps delivery))
measure BP every 5 minutes for 15 minutes
if still not pain free 30 mins after administration then get anaesthetist
unless the woman has an urge to push or the baby’s head is visible, pushing should be delayed for at least 1 hour and longer if the woman wishes, after which actively encourage her to push during contractions.
Do not routinely use oxytocin in the second stage of labour for women with regional analgesia.
how is an epidural topped up
patient controlled- patient presses button every time they feel pain
which has more SEs diamorphine or an epidural
epidural
what are the SEs of an epidural
arrhythmias dizziness hypertension hypotension nausea paraesthesia urinary retention vomiting longer labour infection from insertion site (abscesses) haematoma dural headache nerve damage increases risk of instrumental delivery
what are the risk to the fetus from an epidural
neonatal resp depression
hypotonia
bradycardia
hypotension in mother can cause bradycardia
What observations/assessments are made to assess the progress in labour?
partogram cardiotocography station vaginal exams abdominal palpation (shows descent of head)
what is meconium
early faeces of infant
can be passed due to previous stress of the baby
puts baby at risk of aspiration
what are the different appearances of liquor
clear
meconium stained
blood stained
absent liquor
what is caput
oedema under scalp, more significant in longer labours
when do you worry about moulding
when bones overlapping each other and fixed there- worry about whether head will fit through pelvis
what can be given to increase the strength of contractions
syntocinon (synthetic oxytocin)
what should you do if 2nd stage of labour prolonged
Start on IV oxytocin then reassess in 4 hours
Give epidural
When dilated 10cm and have epidural already then wait an hour to progress naturally (without epidural then will feel urge to push so cant usually wait an hour)
If still failing to progress -> emergency CS
what stage of labour is the baby born
2nd
