lecture 6 normal labour Flashcards
positioning of pelvis
tilted forwards
why do you need things to retain the prgnancy
uterus is adpated to push things out
main hormone in retaining prgnancy
progesterone
in the beginning wht secretes progesterone
corpus luteum
what takes over progesterone production
placenta
what actions does progesterone have on the uterus
dampens the smooth muscle
strengthens the internal os
what is the cerxic
long tube made of connective tissue
what happens to the cervix in labour
softer
thinner
dilates
how does hypervolaemia in pregnancy retain the
inhibiting the hormones at the posterior lobe of the posterior pituitary gland - inhibits contraction
what are the hormones at the posterior lobe of the posterior pituitary gland
oxytocin
vasopressin
how does adrenaline and sympathetic nervous system work
dampens the smooth muscle
strengthens the internal os
inhibits oxytocin
what regulates the activation of adenylate cyclase
relaxin
corticotropin releasing hormone derives from
placenta
when is CRH released into maternal circulation
third trimester
how does corticotropin releasing hormone inhibit labour
inhibits prostoglandin production
how can CRH help labour
increase the contractility of the myometrium
how is oestrogen involved in the birth
sensitises the uterine muscle to oxytocin
where is oxytocin released from
posterior pituitary gland
for birth what reduces progesterone levels
cortisol
how does prostoglandins help birth
increase the myometrium contractility and act as smooth muscle relaxants on the cervical sphincter
what else other than hormones can increase contractility
distension of the uterus ofc
what are the 4 types of pelvis
gynecoid
android
anthropoid
platypelloid
which is the best pelvis for labour
gynecoid
why is … best pelvis for labour
gynecoid because it is shallow, has a generous capacity, it has a wide suprapubic arch and short ischial spine
what protrudes into the passage
ischial spines
how can the ischial spines affect birth
they can affect rotation
which pelvis is usually found in males
android
features of the android pelvis
triangular pelvis inlet and a narrow suprapubic arch and prominent ischial spines
which women would you find the android pelvis
afro carribean (mon)
features of the anthropoid pelvis
oval with the AP diameter being wider than the transverse diameter
with anthropoid pelvises what position are the babies born in
OP
what affect does babies being born in the OP position have
slows labour
which pelvis is the least common
platypelloid
features of the platypelloid
wide suprapubic arch but prominent ischial spines and a prominent sacrum
what features of the vagina may impede labour
scarring
lots of fat around it
what is the pelvic floor important for
flexion and rotation of the head
hwo can the bladder and bowel affect labour
obstruct the head if its full
at the inlet what size is the:
transverse diameter
OP diameter
13cm
12cm
at the outlet what size is the:
transverse diameter
OP diameter
11cm
12.5cm
what muscles make up the pelvic floor
levator ani
coccygeus
what is under the pelvic floor
urogenital diaphragm
what muscle does the urogenital diaphragm contain
deep transverse perineal muscle
what is the most superficial muscle surrounding the anus and vagina
bulbocavernosus muscle
where is the power mainly from
contractions of the uterus
what does the abdominal wall have to help push the baby down
resting tone
what does the uterus have between contractions
resting tone
how can the contraction of the uterus differ in direction
can be co-ordinated or unco-ordinated
what is unco-ordinated contraction
muscle fibers pushing in different directions
what might you do ifunco-ordinated contraction was happening
start poeple on a drip of syntocinon
what is syntocinon
sythetic version of oxytocin
how do the contractions move in the uterus and what is this called
from fundus downwards
fundal dominance
where in the uterus is the contractions longest
fundus
what does the rhythm of the contraction depend on
stage of gestation
stage of labour
what are the contractions called before labour
braxton hicks
how many contractions in the first stage per 10 mins
3
how many contractions in the second stage per 10 mins
4-5
are there contractions after the labour
yes
why are there contractions after the labour
stop blood loss
what is the babys skull made up of
separate bones
what are the babys skull bones joined by
sutuli
what are the bones either side of the baby skull
parietal
what bond is at the back of the babys skull
occipital
where does the sagital suture run
middle
where is the lambdoidal suture
back
what is the most favourable position of baby for labour -describe
head flexed and tucked in
diameter of 9.5cm
what is it called if the head is only partially flexed and what is the diameter
suboccipital frontal
10.5cm
what is the diameter if the babys head is unflexed
11.5cm
what is the baby position with the widest diameter and what size is it
bravison
13cm
hwo can you tell position of baby
feel for the fontanelles vaginally
palpate the abdomen
head facing down position
occipital anterior
head facing up position
occipito posterior
after the head is fully engaged why does the baby move down
pressure of the amniotic fluid
direct pressure from contractions
internal abdominal muscles
extension and straightening of the fetus
what effect can an epidural have on the rotation
relax the muscles of the pelvic floor and cause malrotation and get stuck in the OP or OT position
what is the latent phase
the onset of contractions
regular contractions
3-4cm
what is the first stage
3-4cm to full dilation
how long is the first stage
5 and a half hours
how long is the second stage
1 hour
what does the second stage involve
active and passive
what is the third stage
delivery of the baby to delivery of placenta and membranes
how do changes to the cervix happen in the latent phase
babys head puts pressure on cervix
prostoglandin release
cervix softens and thins
what is fully dilated
10cm
how does the shoulder getting stuck affect the baby
baby breathing
placenta decreasing function
umbilical vein squashed
baby is hypoxic
what does the uterus do to reduce blood loss
contracts down
what is considered a post partem hemorage
loss more than 500 mls
how can labour be measured
partogram
what can stress do to labour
activates the sympathetic nervous system
decreases oxytocin release
why might women not know they need a wee in labour
epidural
lots of pain
what can happen if the bladder is overly stretches
damages the detrusor muscle
why is pain relief important
pain stimulates the sympathetic nervous system and slow labour
how is the progress of labour measured
every 4 hours with a vaginal exam
what is CPD
head too big for pelvis
what happens if CPD is not treated
uterus rupture and mother and baby die
risks of a longer labour
sepsis
prolapse
incontinence
symptoms of sepsis
pyrexia
tachycardia
treatment for septic mother
antibiotics
fluid
delivery
what can high blood pressure be a sign of
pre eclampsia
what can pre eclampisia lead to
fit
how do we avoid tears
test stretchyness of the membrane
what is a third degree tear
tear to the anal sphincter
how should delivery of the head be controlled
should be slowed
what does third stage management involve
injection of syntometrine
what is syntometrine
combination of syntocinon and ergometrine
what is ergometrine
synthetic form of a hormone produced by a fungus = strong contraction
at what speed should women be dilating
1cm an hour
what is TENS
transcutaneous electrical nerve stimulation
how does TENS work
makes the body release endorphin which work as morphine
what is inhlaed gas called
entonox
why do some women not like laughing gas
makes them feel faint/drunk
examples of systemic opiates used
Pethidine
Meptid
morphine
diamorphine
how does systemic opiates work
act on morphine receptors
side effects of systemic opiates
nausea
vomitting
respiratory depression in mum and baby
what can be done about respiratory depression in babys
naloxone can be given
what is an epidural
inserting a catheter into the epidural space and inject local anesthetics and opiates
negatives of epidural
educe the resting tone of the abdominal muscles, it reduces the sensation of the pelvic floor making pushing harder, it also makes you less mobile
how long does epidural take to wear off
4 hours
rare severe risks associated with epidural
spinal abscess
spinal hematoma
spinal damage
what is intermittant auscultation
midwife listens in every 15 mins with a sonicaid
CTG
CTG- cardiotocograph
what happens to babys heart rate when spetic
incr
most common way mothers are compramised
sepsis
hemorrage
causes of hemorage
placenta born first
uterus rupture
