Intrapartum Care Flashcards
(54 cards)
1
Q
Labour may be defined as the onset of regular and painful contractions associated with cervical dilation and descent of the presenting part.
What are the signs of labour?
A
- regular + painful uterine contractions
- a show (shedding of mucous plug)
- rupture of the membranes (not always)
- shortening + dilation of cervix
2
Q
What are features of normal labour?
A
- term (37-42 weeks)
- spontaneous
- smooth progression (contraction + dilatation)
- cephalic presentation
- spontaneous vaginal delivery
- minimal complications for mother/baby
3
Q
What is stage 1 of labour?
A
- From onset of regular painful contractions to full dilatation
- latent phase → 0-3cm dilation
- active phase → 4-10cm dilation
The normal duration in primiparous women is often long, being 0.5-1cm dilation per hour, with an average of 8 hours. In multiparous women this is shorter of 1-2cm per hour with an average of 5 hours.
Head enters pelvis in occipito-lateral position. The head normally delivers in an occipito-anterior position.
Rx → intermittent monitoring of her (BP, pulse, temp) + foetus by CTG; encourage to mobilise + eat light diet; vaginal examinations every 4hrs - progress plotted on partogram; if epidural then an indwelling catheter should be positioned or the bladder emptied every few hrs by ‘in and out’ catheter
4
Q
What is stage 2 of labour?
A
- From full dilatation to delivery of the infant
- 1-2hrs in primiparous, 1hr in multiparous
- ‘passive second stage’ refers to 2nd stage but in absence of pushing (normal)
- followed by ‘active second stage’ refers to active pocess of maternal pushing
- less painful than 1st stage (pushing masks pain)
- if longer than 1 hr (can be left longer if epidural) consider Ventouse extraction, forceps delivery or caesarean
- episiotomy may be necessary following crowning
- associated w/ transient fetal bradycardia
- SROM
- difficulty in passing urine as bladder is displaced + urethra stretched
- rectum pushed in sacrum → defecation
5
Q
What is the immediate care of the neonate following delivery?
A
- no need for immediate cord clamping - about 80mL of blood will be transferred from placenta to baby before cord pulsations cease
- baby’s head should be kept dependent to allow mucus in resp tract to drain - apply oropharyngeal suction if necessary
- clamp cord
- APGAR score assessment for 1 min
- place baby on mother’s abdomen - will encourage bonding + release of oxytocin will encourage uterine contractions
- give vitamin K
- general examination for abnormalities
- wrist label
6
Q
What is stage 3 of labour?
A
- From delivery of infant to delivery of placenta + membranes
- lasts up to 30 mins
- contraction of uterine muscles → venous return from uterus reduced causing congested + burst vessels (trickling of blood) → placenta peeled off uterine wall (retroplacental clot)
- placental site becomes smaller
- strong myometrial contractions reduce uterus in 24hrs to 20weeks gestation size (fundal height)
- increase in uterine vascular resistance
7
Q
What are important things to monitor during labour?
A
- FHR monitored every 15min / continuously via CTG
- contractions assessed every 30 mins
- maternal pulse rate (every 30 min) + maternal BP/temp (every 4hrs)
- abominal + vaginal examination offered every 4hrs
- maternal urine should be checked for ketones + protein every 4hrs
- partogram → allow visual assessment of rate of cervical dilation against expected norm, according to parity of the woman
- membranes/show/bleeding/discharge → speculum; colour; smell; consistency; time
8
Q
What is the role of the foetal and maternal endocrine system in the start of labour?
A
-
Prostaglandins → initiate + maintain labour
- produced in amnion, chorion, decidua, myometrium
- triggered by oestrogen, sweep, vag exam, SROM, infection, uterine activity
-
Oestrogen + oxytocin
- cortisol levels increase from foetal adrenal gland increases towards term → this increases oestrogen → formation of oxytocin receptors in uterine muscles → oxytocin is released by maternal pituitary gland → causes uterus to contract + release of prostaglandin in decidua
- Progesterone: increased foetal corticosteroids inhibit progesterone + fall before labour
9
Q
Painful contractions indicates start of labour.
What are the different features of false vs true labour?
A
10
Q
In regards to anatomy, which parts of the uterus contracts and dilates?
A
- there is fundal dominance
- contractions start + stay longest in fundus + spreads to uterus/cervix
- uterine upper segment → contracts strongly
- uterine lower segment → dilates + contracts less strongly
- there is coordination between strong contraction of upper uterine segment and dilatation of lower segment
- after each contraction → uterine muscle cells become shorter → upper segment of uterus becomes smaller/thicker → uterine cavity becomes smaller → fetus pushed into pelvis
- described as ‘foetal axis pressure’
11
Q
What is meant by effacement and dilatation of the cervix?
A
-
effacement → thinning of the cervix
- In primip = occurs before labour
- In multip = occurs during labour
- dilatation → opening of cervix due to strong contractions + retractions
There is formation of forewater and hindwater. Forewater is small quantity of amniotic fluid in front of presenting part protruding into cervix and hindwater is aminiotic fluid behind the foetus.
12
Q
What is the mechanism of labour + delivery?
A
- Every → engagement in transverse position
- Decent → descent of head into pelvis
- Female → flexion
- I → internal rotation as head hits pelvic floor
- Crown → extension of head during delivery
- Rules → restitution ie. external rotation
- Lovingly → lateral flexion of head to deliver shoulders
13
Q
What can the mechanism of labour be affected by?
A
- Parity
- Foetal weight
- Malposition of head
- Maternal effort
- Contractions
- Epidural
14
Q
What is the management of the third stage of labour?
A
- Active → oxytocic drugs ie. syntometrine, syntocinon + cord clamping and delivery of placenta by controlled cord traction (CCT)
- Physiological → delivery of placenta without oxytocic drug, no early cord clamping, no controlled traction; placenta is delivered by maternal effort + mother position; cord clamped + cut when it has stopped pulsating; can take up to an hour + may be more bleeding; bleeding + vitals closely monitored
15
Q
What are complications of the 3rd stage of labour?
A
- retained placenta
- postpartum haemorrhage
- perineal trauma
- perineal/pelvic haematoma
- uterine inversion
16
Q
What are the different degrees of perineal trauma tears?
A
- 1st degree → skin only
- 2nd degree → pelvic floor (not anal sphincter)
- 3rd degree → anal sphincter involved
- 4th degree → anal mucosa involved
17
Q
The vaginal examination is an essential skill needed when caring for labouring women.
Why is it done?
A
- confirm labour; induction of labour / augmentation
- assess progress of labour (cervix, membranes)
- identify presentation + position of foetus
- artificial rupture of membranes
- exclude cord prolapse in an unengaded head following SROM
- prior to pain relief
18
Q
What are the options for pain relief?
A
- distraction → breathing + relaxation techniques, music, TV
- change positions → beanbags, wedges, stools, birthing balls
- alternative methods → transcutaneous electrical nerve stimulation, water, acupuncture/pressure, reflexology, shiatsu, yoga, hypnosis (including self-hypnosis), homeopathic + herbal remedies
- oral analgesia
- entonox → most commonly used, nitrous oxide
- pethedine/morphine → IM, + antiemetics, takes edge off pain, resp distress, nausea, vomiting
- epidural → local anaesthesia + opiates into epidural space (1/3 usage)
19
Q
What affects perceptions of pain and how can we alleviate pain?
A
Affected by → fear + anxiety; expectations; personality; cultural/sociological factors
We can alleviate by:
- giving info / conversation / encouragement
- participation in planning of care
- meeting midwives + attitudes of staff
- relaxed informal atmosphere + supportive companion(s)
20
Q
CTG (cardiotocography) is a way to monitor the foetal heart rate + maternal uterine contractions in the late second and third trimesters of pregnancy.
What is the mneumonic ‘Dr C BRaVADO’ referring to, when assessing a CTG?
A
- Dr → define risk
- C → contractions
- BRa → baseline rate
- V → variability
- A → accelerations
- D → decelerations
- O → overall impression
21
Q
What is a partogram for?
A
- visual representation of labour
- know when to intervene
- provides info on foetal heart rate, fluids, contractions, cervical dilatation, maternal vital signs, drugs, liquor, bladder + progress of labour
- commenced in active labour
- it assists you in making decisions
22
Q
What is the management of the latent phase of labour?
A
- go home and/or ambulation + continue normal activity
- transfer to antenatal ward
- reassurance, support + explanation
- nutrition + hydration, rest + sleep
- warm bath and pain relief
- allow labour to progress naturally
23
Q
What is the management of the slow active phase of labour?
A
- frequent problem in primip
- hydration + nutrition (if low risk)
- adequate pain relief
- mobilisation / change of position
- artificial rupture of membranes to enhance contractions
- oxytocin to enhance contractions
- monitoring progress of labour
24
Q
What are complications of slow labour?
A
- maternal dehydration + exhaustion
- maternal + foetal infection
- foetal compromise
- operative delivery
- uterine rupture
- postpartum haemorrhage / perineal trauma / fistula
- increased maternal + foetal morbidity
25
What is meant by **abnormal** labour?
* *dystocia = 'difficulty in labour'*
* when there is poor progress OR the foetus shows signs of compromise OR malpresentation OR uterine scar OR labour is induced
* **RFs for abnormal labour** → small women, big baby, malpresentation, malposition, early membrane rupture, soft tissue/pelvic malformation
26
There might be poor progress in the 1st stage of labour.
What are the **causes** of **slow/abnormal labour**?
* **POWER** → uterine power, uterine efficiency
* **PASSENGER** → size, presentation, position
* **PASSAGE** → uterus, cervix, bony pelvis
* **PSYCHE**
27
What is meant by '**prolonged latent phase**'?
* a failure of **thinning** of the lower segment, **effacement** and **dilatation** of the cervix _despite_ several hours of painful contractions
28
What is **primary dysfunctional labour**?
* most common in _first_ labour
* implies slow progress during the **active** phase of labour
* usually associated w/ **inefficient** uterine contractions
29
What is **secondary arrest**?
* implies appropriate progress of labour in the **initial** phase
* but _arrest_ of cervical dilation typically after **7cm**
* usually associated w/ **malpresentation** and **cephalo-pelvic disproportion**
30
**Inefficient uterine action** is the most common cause for abnormal/slow labour. Risk factors include extremes of reproductive age, unusually anxious women, primigravidae and uterine overdistension.
What **two categories** can inefficient uterine action be divided into?
* **Hypotonic inertia:**
* contractions are weak + infrequent
* there is normal uterine tone between contractions
* _Rx_ → rupture of membranes +/- IV oxytocin
* **Hypertonic inertia:**
* contractions are irregular
* high resting basal tone between contractions
* uterine circulation does not return to normal between contractions → foetal distress more likely
* _Rx_ → epidural analgesia w/ IV oxytocin
31
**Cephalo-pelvic disproportion** (CPD) implies anatomical disproportion between the foetal head and maternal pelvis. This can be caused by a large head, small pelvis or both OR relative CPD can occur with malposition of the head.
When should CPD be **suspected** in labour ie. what are the signs suggestive of it?
* _RFs_ → primigravida women of small stature (\<1.6m) with a large baby
* progress slow/stopped despite _efficient_ uterine contractions
* foetal head **not engaged**
* vaginal examination shows severe moulding + caput formation
* head is poorly applied to cervix
Rx → **oxytocin** - for primigravida women - as long as no foetal distress
32
What are examples of **abnormalities of _passage_**?
* Can be _abnormality_ of: bony pelvis, maternal soft tissues, uterus or cervix
* Commonly caused by **fibroids** + severe **scarring** of cervix from ops eg. LLETZ (scar tissue doesn't dilate!)
* **Rx** → normal delivery OR C-section
33
What is the **APGAR** score?
* usually done at 1 and 5 minutes
* \<6 = low
34
What is the management of **poor progress** in labour?
* **Nulliparous woman** → if no foetal probs do early **artificial rupture of membranes** - if still poor progress, then give _IV oxytocin_
* **Oxytocin** will make contractions more, frequent efficient and/or stronger. **Do not** give if suspicion of foetal _distress_. It carries a **risk** of uterine rupture. Monitor w/ **CTG** throughout administration and vaginal examination 2hrs post-administration.
## Footnote
*Major degree of caput and moulding suggests that there is a mechanical obstruction. If strong contractions but little progress it suggests CPD - treat w/ C-section.*
35
**Induction of labour** (IOL) is the process of starting labour artificially. Whilst most women will go into labour spontaneously by week 42 of gestation, roughly 1 in 5 pregnancies will require an induction.
What are the four main **indications** for **induction**?
**4 Ps**
* post dates
* pre-labour rupture of membranes
* pre-eclampsia
* plus diabetes
36
What is the **most common reason** to induce labour?
* **_post-maturity_**
* especially common in **primips**
* increase in stillbirth rate beyond 42 weeks: recommendation is to induce at **41-42 weeks**
* exact timing is dependent on **local policy** and **views of patient**
* NB women undergoing induction _immediately_ become '*higher risk*' pregnancies and therefore require additional monitoring
37
What are the circumstances surrounding **pre-labour rupture of membranes** at term, for induction?
* after _rupture of membranes_, women most likely to labour **within first 24hrs**
* for those who don't, the chances of labour starting spontaneously **decreases** rapidly beyond this point
* at this stage, the risk of **ascending infection** needs to be considered
* therefore induction should be offered to all women _24hrs after spontaneous rupture of membranes if labour has not ensued_
* the guidance is less clear in cases of preterm pre-labour rupture of membranes (ie. \<37 weeks)
38
Why might induction be necessary in women with **previous caesarean section** who hope to have a vaginal birth?
* **VBAC** carries risk of **scar dehiscence**
* uterine scar dehiscence involves the disruption and separation of a preexisting uterine scar → **uterine rupture**
* 1:200 in spontaneous labour
* 1:100 induction/augmentation w/ syntocinon
* 1:20 induction w/ prostin
Induction in this group therefore has to be approached with caution after a discussion of risks with patient and senior involvement
39
The contraindications for induction of labour are generally the same as for **vaginal delivery**. They can be divided into absolute contraindications and relative contraindications.
What are the **contraindications** for induction of labour?
* **ABSOLUTE:**
* cephalopelvic disproportion
* major placenta praevia
* vasa praevia
* cord prolapse
* transverse lie
* active primary genital herpes
* previous classical caesarean section
* **RELATIVE:**
* breech presentation
* triplet or higher order pregnancy
* two or more prev low transverse C-sections
40
What are the **3 stages** of _induced_ labour?
1. **Cervical ripening** - softening, shortening and opening of the cervix, eventually to allow artifical rupture of membranes (equivalent to latent phase of first stage of labour)
2. Artifical rupture of membranes by **amniotomy**
3. **Cervical dilatation** to fully dilated (equiv to active phase of first stage o
41
**Induction**: What happens in **stage 1** (ripening of cervix)?
* **prostaglandins** ripen cervix + have a role in contraction of smooth muscle of uterus
* vaginal prostaglandin E2 **pessaries** ("propess") for _nullips_ and **gel** ("prostin") for _multips_
* _pessary_: 1 cycle = 1 dose/24hrs
* _tablet/gel_: 1 cycle = 1st dose, plus 2nd dose if labour not started 6 hours later
* they soften and shorten cervix and cause uterine tightening
* may not be necessary in **multiparous** women as cervix often partially open
* **_risk_** of hyperstimulation and foetal distress: foetal heart intermittently monitored w/ CTG
42
**Induction**: What happens in **stage 2** (amniotomy)?
* membranes ruptured artificially w/ **amnihook** during vag exam
* possible once cervix sufficiently effaced (_Bishop_ _score_)
* risk of cord prolapse if presenting part high
* this process releases **PGs** in attempt to expedite labour
43
**Induction**: What happens in **stage 3** (cervical dilatation)?
* **IV oxytocin** (syntocinon) used to generate **uterine contractions**
* dose titrated to achieve 3-4 strong contractions _every 10 mins_
* risk of uterine **hyperstimulation**, although more easily reversible as infusion can be turned off
* foetal wellbeing needs to be monitored using continuous **CTG**
* from this stage progress is monitored using a **partogram**
44
The membrane sweep is offered at 40 and 41 weeks’ gestation to nulliparous women, and 41 weeks to multiparous women.
What is a **membrane sweep**?
* _adjunct_ of induction of labour
* increases likelihood of **spontaneous labour** and _avoid_ induction in some cases
* finger passed between cervix and membranes at time of digital vaginal examination
* thought to cause release of hormones which may trigger labour
45
**The bishop score** is an assessment of ‘cervical ripeness‘ based on measurements taken during vaginal examination. It is checked prior to induction, and during induction to assess progress (6 hours post-table/gel, 24 hours post-pessary).
How is the modified Bishop score **calculated** and what does the result mean?
* BS **\<5** → further prostin needed
* BS **5-8** → consider further prostin - artifical rupture may be possible
* BS **\>8** → amniotomy, further prostin not required
46
What are the **complications/risks** of induction?
* **failure of induction** (15%) → offer a further cycle of prostaglandins, or a C-section
* **uterine hyperstimulation** (1-5%) → contractions last too long or are too frequent, leading to foetal distress; can be managed w/ tocolytic agents (anti-contraction) such as terbutaline
* **cord prolapse** → can occur at time of amniotomy, particularly if presentation of fetal head is high
* **infection** → risk reduced by using pessary vs tablet/gel, as fewer vaginal examinations are required to check progress
* **pain** → IOL often more painful than spontaneous labour; often epidural analgesia used
* **inc rate of further intervention vs spontaneous labour** → 22% require emergency C-sections + 15% require instrumental deliveries
* **uterine rupture** (rare)
47
What is **augmentation** and how is it different to induction?
If active labour has started on its own but contractions have slowed down or completely stopped, steps need to be taken to help labour progress (augmentation). **Augmentation** will be done when:
* Active labour has started, but your contractions are **weak** or **irregular** or have **stopped** entirely
* You have gone into active labour, but the amniotic sac has not ruptured on its own. In this case, your doctor or nurse midwife may rupture the amniotic sac (**amniotomy**) to augment labour. If labour still does not progress, **oxytocin** (Pitocin) may be given to make the uterus contract.
* Active labour has started and the amniotic sac has ruptured on its own, but labour still is not progressing. **Oxytocin** (Pitocin) may be given to make the uterus contract.
48
There are two main instruments used in **operative deliveries** – the **ventouse** and the **forceps**.
In general, the first instrument used is the most likely to succeed. The choice is **operator dependent**, but _forceps_ tend to have a _lower risk_ of **fetal** complications, and a _higher risk_ of **maternal** complications. The general rule is, if after **three contractions** and pulls with any instrument there is no reasonable progress, the attempt should be abandoned.
What is the **ventouse** and how is it used?
* instrument that attaches a cup to **foetal head** via a **vacuum**
* A) an electrical pump attached to a **siliastic cup** - only suitable if foetus in an occipital-anterior position
* B) a hand-held, disposable device AKA "**Kiwi**" - an omni-cup, can be used for all foetal positions and rotational deliveries
* to use ventouse, cup is applied with its centre over the **flexion point** on foetal skull (in midline, 3cm anterior to posterior fontanelle)
* during uterine contractions, traction is applied perpendicular to cup
Ventouse deliveries are associated with: **lower success rate, less maternal perineal injuries, less pain, more cephalhaematoma, more subgaleal haematoma + more foetal retinal haemorrhage**
49
What are **forceps**, _how_ are they used and what are they _associated_ with?
* _double-bladed_ instruments
* **Rhodes, Neville-Barnes** or **Simpsons** → used for OA positions
* **Wrigley's** → used at caesarian section
* **Kielland's** → for rotational deliveries
* blades are introduced into pelvis, taking care not to cause trauma to maternal tissue + applied around sides of foetal head w/ blades then locked together
* **gentle traction** applied during uterine contractions, following J shape of the maternal pelvis
Use of forceps associated with: **higher rate of 3rd/4th degree tears, less often used to rotate + doesn't require maternal effort.**
50
The decision to perform an operative vaginal delivery should be based on the entire clinical scenario in the **2nd stage of labour** - *is there a valid clinical indication to intervene? Is the patient a suitable case for an instrumental delivery?*
What are the common **indications** of operative/assisted vaginal delivery?
51
In general, what are the **pre-requisites** for instrumental delivery?
* fully dilated
* ruptured membranes
* cephalic presentation
* defined foetal position
* foetal head at least level of ischial spines, and no more than 1/5 palpable per abdomen
* empty bladder
* adequate pain relief
* adequate maternal pelvis
52
What are **contraindications** for instrumental delivery?
* **ABSOLUTE**:
* unengaged foetal head in singleton pregnancies
* incompletely dilated cervix in singleton pregnancies
* true cephalo-pelvic disproportion (where foetal head is too large to pass through maternal pelvis)
* breech + face presentations, and most brow presentations
* preterm gestation (\<34wks) for ventouse
* high likelihood of any foetal coagulation disorder for ventouse
* **RELATIVE**:
* severe non-reassuring foetal status w/ station of head above level of pelvic floor - ie. foetal scalp not visible
* delivery of second twin when head has not quite engaged or the cervix has reformed
* prolapse of umbilical cord w/ foetal compromise when cervix is completely dilated and station is mid-cavity
53
What are the **foetal** and **maternal** **complications** of operative vaginal delivery?
* **FOETAL**:
* neonatal jaundice
* scalp lacerations
* cephalhaematoma
* subgaleal haematoma
* facial bruising
* facial nerve damage
* skull fractures
* retinal haemorrhage
* **MATERNAL**:
* vaginal tears
* 3rd/4th degree tears (1:100 normal delivery, 4:100 ventouse, 10:100 forceps)
* VTE
* incontinence
* PPH
* shoulder dystocia
* infection
54
Risk factors for pre-term labour include multi-foetal pregnancy, prev hx of preterm delivery or late miscarriage after 14 weeks and they're also more common after cervical surgery.
What is **pre-term labour**?
* labour starting before **37/40**
* **7-10%** of deliveries in UK
* earlier the gestation, the greater the neonatal **morbidity** + **mortality**
* _mechanisms_ of preterm labour:
* **stretching** of myometrium
* cervical **thinning** or shortening
* ascending **infection**
* interventions include progesterone supplementation + cervical stitch
* screening involves **cervical length measurement**
Management depends on two key factors: **gestation** and **rupture of membranes**
