WH: Labour Flashcards
When does labour and delivery usually occur?
between 37 - 42 weeks
how many stages does labour have?
3 stages
When does first stage of labour start and end?
starts from onset of labour (true contractions) until 10 cm cervical dilation
How many phases are there in the first stage of labour? what are they called ?
3 phases to first stage of labour
- Latent
- Active
- Transition
describe latent phase of labour? how many cm cervical dilation? rate of cervical dilation? describe the contraction?
Latent phase (Phase 1 of stage 1)
- 0 - 3cm cervical dilation
- 0.5cm/hr
- irregular contractions
describe active phase of labour? how many cm cervical dilation? rate of cervical dilation? describe the contraction?
Active phase (phase 2 of stage 1)
- 3 - 7 cm cervical dilation
- 1cm/hr
- regular contractions
describe the transition phase of labour? how many cm cervical dilation? rate of cervical dilation? describe the contraction?
Transition phase (phase 3 of stage 1)
- 7-10cm cervical dilation
- 1cm/hr
- strong and regular contractions
what 2 things happen to the cervic during the first stage of labour?
- Dilatation (opening up/widening)
- Effacement (thinning out)
What are the 2 layers to the fetal membranes ? how do they change before labour?
chorion + amnion
- They become weaker Ian prep for labour
What is the show? what does it usually do? why does it come out?
mucus plug preventing bacteria entrance falls out
- creates space for baby
What are Braxton-hicks contractions ? when do they occur?
not true contraction in 2nd/3rd trimester
- not labour (they do not progress)
What marks the beginning and end of the second stage of labour?
from 10cm cervical dilatation until delivery of baby
What does success of the second stage of labour depend on?
3 (4) Ps
- Power
- Passenger
- Passage
- (Psyche)
What does power refer to in terms of the second stage of labour?
strength of uterine contractions
What does passenger refer to in terms of the second stage of labour?
the fetus
- Size
- Attitude (posture)
- Lie
- Presentation
what does passage refer to in terms of the second stage of labour?
size and shape of the passageway (mainly pelvis)
what marks the beginning and end of the third stage of labour?
from delivery of baby until delivery of placenta
When should you consider active management of the third stage of labour? (2)
- haemorrhage
- more than 60 min delay in placenta delivery
What drug is often sued in active management of third stage of labour? how does it work?
IM oxytocin helps uterus contract + expel placenta
Name some signs of labour
- Show (mucus plug)
- SROM (all at once or trickle)
- cervical dilatation 10 cm
- Regular painful contractions
what is failure to progress in labour? leads to?
labour not delivering at a satisfactory rate => increase risk to mother + fetus
what is used to measure progress during first stage of labour?
monitored for progress using a partogram
what can be used to help progress the second stage of labour? (6)
- Changing positions
- Encouragement
- Analgesia
- Oxytocin
- Instrumental delivery
- CS
What are the 8 key fetal stages to a vaginal birth?
- Descent
- Engagement
- Neck flexion
- Internal rotation
- Crowning
- Extension of the presenting part
- Restitution + external rotation
- Delivery of shoulders + body
what is fetal descent ? when does this happen ?
the fetus descent into the pelvis
- around 38 weeks onward
what is fetal descent encouraged by? (3)
- Increased abdo muscle tone (contraction)
- Increased frequency + strength of contractions
- Increased amniotic fluid pressure
What is fetal engagement ?
when the latest diameter of fetal head descends into maternal pelvis
- the head turns to allow widest part of head through widest part of pelvic inlet
What triggers pelvic neck flexion? why is this important?
fetal head comes in contact with pelvis floor => cervical flexion
- allows for smaller head circumference
what is the smallest fetal head circumference ?
suboccipitobregmatic
describe the movement of internal rotation of the fetal head? what encourages this?
head rates from R or L occipto transfers => occipital anterior position
- encourage by gutter shape of pelvis
What is crowning?
widest part of head passes narrowest part of pelvis
what happens during the extension of the presenting part of labour?
fetal head extends
what is fetal restitution and external rotation?
head externally rotates to face R or L medial thigh
which shoulder comes out first in delivery?
anterior shoulder then posterior should then rest of body
What is preterm birth?
birth before 37 weeks gestation
What does ROM stand for ? and mean?
Rupture of membranes
- the amniotic sac has ruptured (+ leakage of fluid)
what does SROM stand for? and mean?
Spontaneous rupture of membranes (SROM)
- The amniotic sac has rupture spontaneously
What does PROM stand for? and mean?
Prelabour rupture of membranes (PROM)
- the amniotic sac has ruptured before the onset of labour
what does P-PROM stand for? and mean?
Preterm prelabour rupture of membranes (P-PROM)
- the amniotic sac has ruptured (and release amniotic fluid) before the onset of labour and before 37 weeks gestation (preterm)
What is prolonged ROM?
the amniotic sac ruptures more than 18 hours before delivery
When are babies considered viable? why is this important
from 24 weeks onward
- resuscitation is offered as there is increased chase of survival
describe the preterm ranges
- Extreme preterm
- Very preterm
- Moderate/late preterm
- full term
- Overdue
- Extreme preterm: <28
- Very preterm: 28-32
- Moderate/late preterm: 32-37
- full term: 37-42
- Overdue: >42
what can be used as prophylaxis for preterm labour?
- Vaginal progesterone
- Cervical cerclage
how does progesterone work as prophylaxis for preterm labour?
it maintains pregnancy + prevents labour by decreasing activity of myometrium + prevents cervix remodelling
How does cervical cerclage work? when removed?
add stitch to cervix to keep it closed
- removed in labour or term
How is P-PROM diagnosed?
history and speculum exam
- women is before 37 weeks, signs of ROM, no signs of labour
what would be seen on speculum exam of P-PROM?
amniotic fluid pooling in vagina
P-PROM management ? explain
Need to weigh up risk of staying in vs delivery (infection vs prem)
- prophylactic Abx (preven chorioamnionitis dev)
- IOL
From When is IOL considered in P-PROM?
from around 34 weeks
What is preterm labour with intact membranes?
regular painful contractions + cervical dilatation without amniotic sac rupture
How is preterm labour with intact membranes diagnosed?
speculum exam (cervical dilatation)
TVUS
preterm labour with intact membranes management?
- Fetal monitoring
- Tocolysis (short term measure (<48 hrs))
- Antenatal steroids
- IV Mg sulphate
what is tocolysis? when (how many weeks gestation)
using medications to stop contractions (between 24 and 33+6 weeks)
what is main drug used in tocolysis? what type of drug is this?
Nifedipine (CCB)
what do antenatal steroids do?
help develop fetal lungs => decrease risk of RDS (for less than 36 weeks gestation)
what do IV Mg Sulphate do? decrease risk of what?
protest fetal brain in premature delivery
- decrease risk of CP
woman just given birth has low RR, low BP and absent reflexes. What should you be concerned about?
Magnesium toxicity
(caused by IV Mg sulphate)
What is Induction of Labour (IOL)?
the use of medications or manoeuvres to stimulate onset of labour
name some indications for IOL?
- 41-42 weeks gestation
- Pre labour ROM
- FGR
- pre-eclampsia
- fetal death
what does IOL reduce the risk of in pre labour ROM ?
reduce risk of ascending infection (chorioamnionitis)
what does IOL reduce the risk of in 41-42 weeks gestation
reduce risk of stillbirth
what score is used to determine whether to induce labour?
the bishop score
what is the bishop score an assessment of? what does low score mean ?
assessment of cervical ripness
(determine whether to induce labour)
- lower score => less ripe so consider prostaglandins
Name some options for IOL? (3)
- membrane weep
- Vaginal prostaglandins
- Artificial ROM with oxytocin infusion
what prostaglandin is used in IOL? drug name?
prostaglandin E2
(dinoprostone)
what does vaginal progesterone do? what is it used in?
stimulate cervix + uterus to cause onset of labour
- IOL
name a side effect of vaginal prostaglandin use for IOL? causes what?
SE: can cause uterine hyperstiumulation => fetal distress
what is done throughout IOL?
cardiotocography (CTG) to assess fetal HR + uterine contractions
What is oxytocin ? produced and secreted where?
It is a hormone produced by the hypothalamus and secreted by the posterior Pituitary
what does oxytocin stimulate ? (4)
- Ripening of cervix (in preparation for delivery)
- Contractions of uterus (in labour)
- Aid lactation after childbirth
- Social interactions (sexual arousal, romantic attachment, parent-infant bonding)
what are oxytocin infusions used for? (4)
- IOL
- Progress labour
- Progress frequency + strength of uterine contractions
- Prevent or treat PPH
What is ergometrine used in? how does it work?
(drugs in labour)
- used in a active management of the 3rd stage of labour
-stimulate smooth muscle contraction in uterus + blood vessels
What are prostaglandins ? what are they used in?
local hormones that stimulate contraction of uterine muscles + cervical ripening
- useful in IOL
What prostaglandin is used in IOL? type and drug name?
Prostaglandin E2 (dinoprostone)
What is mifepristone? used in what?
anti-progesterone that blocks action of progesterone => halt pregnancy + ripens cervix + enhances effects of prostaglandins (uterine contractions)
- One of the drugs used in TOP
What is nifedipine? how does it work? and what is it used in?
CCb that reduces smooth muscle contraction in blood vessels + uterus
- Used in tocolysis (Premature labour) and to reduced BP (preeclampsia)
What is the first level of analgesia used in labour?
paracetamol often used in early labour (+/- codeine)
what analgesia is avoided in pregnancy?
NSAIDs are avoided in pregnancy and labour
what is another name for gas + air ? What drugs are in it ?
Entonox
- 50% nitrous oxide
- 50% oxygen
what kind of pain relief does entonox provide
gas+air
- short term pain relief used during contractions
name some side effects of entonox (3)
gas+air
- light headedness
- Nausea
- Sleepiness
what is an epidural?
local anaesthetic administered via a Catheter into the epidrual space
SE of epidural? (4)
- Headache after insertion
- Hypotension
- Increase probability of instrumental delivery
- Motor weakness
how is it that an epidural might cause motor weakness?
due to Catheter being in subarachnoid space rather epidural
What is an instrumental delivery ?
It is a vaginal delivery assisted by venous suction cup of forceps
how many births in the UK are via instrumental delivery
about 10%
what is given to the mother with a instrumental delivery? why?
single dose co-amoxiclave (broad spectrum Abx) to reduce risk of maternal infection
indications for instrumental delivery? (3)
- Failure to progress
- Fetal distress
- Maternal exhaustion
What analgesia increases the risk of instrumental delivery ?
epidural
what are the requirements for consideration of instrumental delivery ? (state of the mother) (3)
- Fully dilated
- ruptured membranes
- Cephalic presentation
what risks are there to the mother with an instrumental delivery ? (5)
- PPH
- Perineal tears
- Epiostomy
- Injury to anal sphincter
- Incontinence (future)
what risks are there to the baby with a ventouse instrumental delivery ?
cephalohaematoma
what risks are there to the baby with a forceps instrumental delivery ?
facial nerve palsy
What causes a perineal tear?
it occurs when external vaginal opening is too narrow to accommodate the baby => skin + tissue tears
RF for perineal tears? (5)
- First birth (nulliparity)
- Are babies (>4kg)
- Shoulder dystocia
- Instrumental delivery
- Occipito-posterior position
how many different categories of perineal tears are there?
4
what is a first degree perineal tear?
Injury limited to frenulum of labia minora + superficial skin
what is second degree perineal tear?
perineal muscles (but not anal sphincter)
what is a third degree perineal tear?
perineal muscles and anal sphincter but not rectal mucosa
what is a 4th degree perineal tear?
perineal muscles and anal sphincter and rectal mucosa
Which degrees of perineal tears require sutures?
2,3,4
What is done to mange perineal tears?
- sutures
- Broad spectrum abs (decrease infection risk)
- physiotherapy (decrease risk + severity of incontinence)
name some complications of perineal tears? short term? long term?
- Pain, infection, bleeding, wound dehiscence
- long term: urinary incontinence, anal incontinence, dyspareunia
What is a caesarian section?
it is a surgical operation to deliver baby via an incision in abdo + uterus
(elective or emergency)
What is an elective CS? when? what anaesthetic ?
usually performed under spinal anaesthetic after 39 weeks
name some indications for an elective CS ?
- Prev CS
- Symptomatic after significant perineal tear
- Placenta praevia
- Vasa praevia
- Breech presentation
- Multiple pregnancy
What category of CS is an elective one ?
category 4 (highest one)
what does category 1 CS mean? how quickly should procedure be done?
emergency
- <30min
what are the layers to get through to do a CS? (8)
- Skin
- Sub cut tissue
- fascia/rectus sheath
- Rectus abdominus muscles
- peritoneum
- Vesicoutero peritonium
- Uterus
- Amniotic sac
name the layers of the uterus from superficial to deep?
superficial
- Perimetrium
- Myometrium
- Endometrium
deep
what drug is used in the anaesthetic for an elective CS?
spinal anaesthetic: local (lidocaine) into CSF
name some complications of CS ?
- PPH
- Wound infection
- Wound dehiscence
- ## Damage to local structures
What is given to mother doing CS to reduce risk of complications ?
- Prophylactic Abx
- Oxytocin (reduce PPH risk)
- VTE prophylaxis (LMWH)
- H2 receptor antagonist
- anti d
why is H2 receptor agonist given during CS ?
to reduce the risk of aspiration of gastric contents into lungs
(at higher risk diet pregnant women lying flat for CS)
what risks re there to the baby in a CS ?
- Laceration
- Increase incidence of transient tachypnoea of newborn
What is an important risk to consider in a vainal birth after caesarian (VBAC) ?
uterine scar rupture
(advice to continue with CS after the initial one)
Why are elective Caesarean sections typically planned for >39 weeks gestation?
Reduce risk of respiratory distress in newborn
Which medication is typically administered intra-operatively to aid delivery of the placenta?
oxytocin
What are the 2 management approaches to the third stage of labour?
physiological or active management
what does physiological management of the thirds stage of labour involve?
where the placenta is delivered by maternal effort only
what does active management of the thirds stage of labour involve? (2)
- IM oxytocin: helps uterus contract
- Traction to the umbilical cord
what does active management of the third stage of labour achieve ?
- Shorten the 3rd stage of labour
- Reduce risk of bleeding
What is fetal lie (give some examples) ? and what examination do you do to confirm it ?
relationship between the long axis of fetus + mother (longitudinal, transverse, oblique)
- abdo exam to confirm
What is fetal presentation (give some examples) ? and what examination do you do to confirm it ?
The fetal part that first enter the pelvis (cephalic, shoulder, brow, breech)
- abdo exam to confirm
What is fetal position (give some examples) ? and what examination do you do to confirm it ?
Position of fetal head as exists birth canal (sally occipto-anterior)
- vaginal exam to confirm
RF for abnorma fetal lie, malpresentation, malposition ? (3)
- Prematurity
- Multiple pregnancy
- Uterine abnormailites
Investigations for suspected abnormal fetal lie/presentation/position ?
should be confirmed with USS
management of abnormal fetal lie ? how many weeks gestation ? success rate ?
- External cephalic version (ECV): from 36-38 weeks
- about 50% success rate
malpresentation management ? in which presentation is CS necessary ?
- Breech: ECV or vaginal breech dev or CS
- CS necessary in Brow or shoulder presentation
