Normal Labour and Puerperium Flashcards
What is the function of progesteron in labour?
keeps uterus settles by hindering contractility of myocytes and preventing formation of gap junctions
what is the function of estrogen in labour?
makes uterus contract and promotes prostaglandin production
What is the function of oxytocin in labour?
intiate and sustains contractions; acts on decidual tissue to promote prostaglandin release
Where is oxytocin synthesised?
directly in decidual and extraembryonic fetal tissues and in the placenta
How is labour initiated?
change in oestrogen/progesterone ratio; fetal drenal and pituitary hormones; mymotrial stretch; fergusons reflex
What is Fergusons Reflex?
neuroendocrine reflex comprimsing the self-sustaining cycle of uterine contractions initiated by pressure at the cervix or vaginal walls
What does pulmonary surfactant secreted into amniotic fluid caused?
stimulates prostaglandin synthesis
What does an increasein fetal cortisol cause?
increase in maternal estriol
What is the Bishops score used for?
determine whether it is safe to induce labour
what factors are part of Bishops score?
position; consistency; effacement; dilatation; station
What is retraction?
when muscles relax do not return to theri former length but become progressivley shorter
What is the function of retraction?
progressively reduce uterine capacity and increase the thickenss of the uterine wall
What is cervical effacement?
thinning and stretching of cervic by retraction
What is “show”?
effacemnt and dilatation of cervic loosens the membranes from the internal os with slight bleeding and frees the mucous plug or operculum
What are the 2 phases of the 1st stage of labour?
latent and active phase
When does the latent phase of labour last?
upto 3-4cms dilatation
When is the active stageo f labour?
4-10cms
What happens during hte second stage of labour?
full dilatation–delivery of baby
What happens during hte third stage of labour?
delivery of baby–expulsion of placenta and membranes
What ar ethe features of the latent phase of labour?
mild irregular uterine contractions; cervix shortens and softens; duration varibale
What are the features of active phase?
slow decent of the presenting part, contractions progressively bcome more rhythmix and stronger
What is normal progression of active phase?
1-2cms per hour
What is the average width of the fetal head?
9.5cm
What is prolonged second stage with regional analgesia in nulliparous woman?
> 3 hours
what is prolonged second stage in nulliparous woman without regional analgesia?
> 2 hours
What is prologned second stage in multiparous woman with regional anlagesia?
> 2hours
What is prolonged second stage in multiparous woman wihtout regional anaesthesiaa?
> 1hour
What is the average duration of third stage?
10 minutes
What is the upper limit of normal duration of thrid stage?
<30mins
Why is active managemnt of the thrid stage preferred?
lower risk of PPH
What is active managmetn of third stage of labour?
prophylactic use of syntometerine or oxytocin; cord clamping and cutting; controlled cord tractio nand bladder emtying
What causes cervical softening in labour?
increase in hyaluronic acid increases molecules among collagen fibres; decreased bridging among collagen fibres decreases firmness of cervic
What causes cervical ripening in labour?
decrease in collagen fibre alignemnt; fibre strenght; tensile strenght of cervical matrix and increase in cervical decorin
When can Braxton Hicks contractions begin?
6 weeks into pregnancy but more usually in 3rd trimester
What is a contraction described as?
wave-like
What are the features of Braxton-Hicks contractions?
irregular- do not increase infrequency or intensity; resolve iwth ambulation or change in activity; relatively painless
Where is uterine muscle found in the highest density?
fundus
Where is the pacemaker of the uterus thought to be?
region of tubal ostia; wave spreads in a downward fashion
What is the difference between the upper and lower segments of the uterus?
upper- contracts and retracts; lower segment and cervix stretch; dilate and relax
What is the nromal frequency of contractions?
upto 3/4 in 10 minutes
What is the max duration of contractions?
45s
What is engagement?
more than 50% of the presenting part has descended into the pelvis
What is 5/5th palpable?
all of the head can be felt in the abdomen
What is zero fifths palpable?
none of the head can be felt in the abdomen
What parameters are involved in the cervical assessment?
effacement; dilatation; firmness; position; station
What features are felt vaginally to assess the position of the fetal head?
posterior fontanelle
How often should vaginal examination be carried out during labour?
every 4 hours
What is an anthropoid pelvis?
oval shaped inlet with large AP diameter and comparitively smaller transverse diameter
What is an android pelvis?
heart-shaped inlet and narrower from the front
what race tends to have android pelvis
afro-carribean
What type of pelvis is most suited to childbirth?
gynaecoid pelvis
What is the normal fetal lie?
longitudinal
what is the normal fetal presentation?
cephalic
What is the normal fetal head position?
occipito-anterior
What is the ideal fetal head position for engagment?
occipito-transverse
What are the seven cardinal movements of the babies head in the pelvis?
engagement; descent; flexion; internal rotation; crowning and extension; external rotation (optiomal position for shoulder) and expulsion
Which shoulder should come first?
anterior
What is crowning?
appearance of a large segment of fetal head at the introitus
What does crowning feel like?
burning and stinging feeling for mother
What 3 signs indicate placental separation?
uterus contracts; hardens and rises
umbilical cordlengthens permanently and gush of blood variable in amount
What is the plane of placental separation?
spongy layer of decidua basalis
What causes the placenta to separate?
shearing force of uterine contractions
What is normal blood loss during labour?
less than 500mls
When is blood loss during labour significantly abnormal?
more than 1500mls
How is haemostasis after delivery achieved?
tonic contraction- uterine muscles strangulate the blood vessels; thrombosis of the torn vessel ends- hypercoaguable
How long does it take tissues to return to non-pregnant state?
6 weels
How long does bloodstained discharge continue after birth?
10-14 days
What is lochia?
vaginal discharge containing blood, mucus and endometrial castings
How long does it take the endometrium to regenerate?
end of a week
What initiates lactation?
placental expulsion
What is the widest diameter of the pelvis at the pelvic inelt?
transverse diameter
what is the widest diameter at the pelvic outlet?
AP
What are the maternal indications for IOL?
pre-eclampsia; poor obstetric history; medical disorders-renal /CTD; post-dates; DM; obstetric cholestasis
What are the fetal indications for IOL?
suspected IUGR; rhesus isoimmunisation; antepartum haemorrhage; PROM
What is premature rupture of membranes defined as?
rupture of membranes more than an hour before the onset of labour
What is used to assess if it safe to induce labour?
Bishop’s score
What medication can be used to induce labour?
prostaglandins- prostin gel/ pessary
What ar ethe mechanical methods of IOL?
membrane sweep; foley balloon catheter
What is the surgical IOL?
amniotomy
What is the latent phase of labour defined as?
<4cm dilated
What is the managemtn of the latent phase?
triage and assessment; look at pain relief; encourage to be at home
How often should VE be done in labour?
4hrly
How often should temp and BP be done during labour?
4hrly
How often should the pulse be taken in labour?
hourly
How often should fetal heart monitoring take place in the 1st stage?
1min after a contraction every 15 mins
How often should fetal heart monitoring take place in hte 2nd stage?
every 5 mins
Waht are the interventions for failure to progress in the second stage?
episiotomy; instrumental delivery; C/s
What is active managemnt of the thrid stage?
routine use of uterotonic drugs; deferred clamping and cutting of the cord; controlled cord traction after signs of separation
Why is the third stage managed actively vs passively?
shortens it; reduces the risk of serious haemorrhage and transufions
What are the risks associated with active amangemtn of the thrid stage?
nausea and vomiting; haemorrhage of more than a litre; blood transfusion
What is delay in the third stage defined as with active mx?
more than 30 mins
What is delay in third stage with physiological mx?
more than 60 minutes
What is the management of delay in the third stage?
manual removal of placenta under GA
What is the treatment for PPH?
empty bladder; uterine massage; uretotonic drugs; IV fluids; controlled cord traction; give O2
