Obstetrics 1 - Labour and Delivery Flashcards
(129 cards)
1
Q
Define onset of labour
A
Regular uterine contractions, progressive cervical effacement and dilatation
2
Q
What occurs in the prelabour/latent phase?
A
Cervical ripening and softening
Irregular contractions
“show” - mucous plug
3
Q
What is engagement of the foetal head, and when does it occur?
A
Widest part of presenting part passes through the brim of the pelvis
2 weeks before delivery
4
Q
What is the station when assessing a woman in labour?
A
The relationship between the lowest point of the presenting part and the ischial spines
5
Q
What is the altitude when assessing a woman in labour?
A
Whether the presenting part is flexed or deflexed
6
Q
Define the lie of the foetus
A
The relationship between the long axis of the foetus and the long axis of the uterus
7
Q
How often should foetal heart rate (FHR) be monitored in labour?
A
every 15 minutes, or continuously with a CTG
8
Q
How often should BP and temperature be monitored in labour
A
4-hourly
9
Q
At what position does the head enter the pelvis?
A
Occipto-lateral position
Delivers in the occipito-anterior position
10
Q
When does the foetus internally rotate to the occipito-anterior position?
A
At the level of the ischial spines
11
Q
What is crowning?
A
Extension of the head and distension of the perineum
12
Q
At what level do the shoulders externally rotate?
A
Level of the ischial spines
13
Q
How does delivery of the anterior shoulder occur?
A
Lateral flexion of the trunk posteriorly
14
Q
How does delivery of the posterior shoulder occur?
A
Lateral flexion of the trunk anteriorly
15
Q
Define the latent phase
A
Period taken for the cervix to completely efface and dilate to 3cm
16
Q
Define the active phase
A
Dilatation of the cervix from 3cm to 10cm
17
Q
What are mild, irregular, non-progressive contractions that occur from 30 weeks gestation?
A
Braxton-Hicks contractions
18
Q
How is a delay in the active phase of labour identified?
A
Progress on the partogram falls to the right of the alert line
19
Q
Define failure to progress in the active phase of labour
A
Failure of cervix to dilate 1cm/hour
20
Q
What are the two types of delayed progression?
A
Primary - slow in early active phase
Secondary - slowing after previous adequate progress
21
Q
What are the 3Ps (causes of delayed progression)?
A
Power - inefficient uterine activity
Passenger - Malposition/presentation/large baby
Passage - Inadequate pelvic
Or a combination
22
Q
When is the second stage of labour?
A
Time from full cervical dilatation to delivery
23
Q
Why is there a delay in cord clamping?
A
Higher rates of haematocrit in the neonate to allow the baby to have a normal full blood volume and decreases the risk of placental complications
24
Q
How often after delivery is the condition of the baby assessed?
A
At 1, 5, and 10 minutes
25
What score is used to assess the condition of the baby?
Apgar score
26
When would you suspect failure to progress in nulliparous women?
Delivery is not imminent after 1 hour of active pushing
| VE, review by obstetrician, consider instrumental/CS
27
When would you diagnose failure to progress in multiparous women?
Delivery is not imminent after 1 hour of active pushing
| Review by obstetrician, consider instrumental/CS
28
What is the third stage of labour?
The duration from delivery of the baby to delivery of the placenta and membranes
29
Describe physiological management of the third stage of labour
No uterotonics
Cord is allowed to stop pulsating before it is cut
Placenta delivered by maternal effort alone
30
Describe active management of the third stage of labour
Uterotonics - IM Syntometrine
Early clamping and cutting of the cord
Controlled cord traction
31
What are the indications for Syntometrine?
Active management of the third stage of labour
| Prevention of PPH
32
When should physiological management of the third stage of labour change to active management?
Haemorrhage
Failure to deliver placenta in one hour
Maternal desire
33
How do you manage patients with an increased risk of PPH?
40IU oxytocin in 500mL saline for 3-4 hours
34
What indicates placental separation (after delivery)?
Firm uterus, 20 week size
Cord lengthens
Separation bleeding
35
When is intermittent auscultation of FHR appropriate?
No foetal or maternal risk factors
Perform for one minute after a contraction
Every 15 mins in first stage, every 5 mins in 2nd stage
36
Give 3 maternal risk factors that indicate the need for electronic foetal monitoring (EFM)
```
Previous CS
Cardiac problems
Pre-eclampsia
Post-term pregnancy
PROM
Induction of labour
Diabetes
APH
```
37
Give 3 foetal risk factors the indicate the need for EFM
```
IUGR
Prematurity
Oligohydramnios
Multiple pregnancy
Meconium liqor
Breech presentation
```
38
Give 3 intrapartum risk factors the indicate the need for EFM
```
Oxytocin augmentation of labour
Epidural
Intrapartum bleeding
Prolonged labour
Abnormal FHR on intermittent auscultation
```
39
10% of cerebral palsy is caused by what during labour?
Intrapartum hypoxia during uterine contractions
40
What are the four components of CTG assessment?
Baseline rate, baseline variability, acceleration, deceleration
41
What are accelerations/decelerations as seen on the CTG?
transient rise/reduction in FHR by at least 15 beats over baseline, lasting >15s
42
How is foetal hypoxia or heart block indicated on the CTG?
Decreased variability
43
Which drugs can cause decreased variability on the CTG?
Methyldopa, narcotic analgesia, MgSO4
44
How is foetal sleep cycle shown on the CTG?
Decreased variability for less than 40 minutes
45
Define baseline foetal bradycardia
Baseline FHR <110BPM
46
Define baseline foetal tachycardia
Baseline FHR >160BPM
47
What is the difference between early and late decelerations on the CTG?
Early - uniform in appearance and timing with contraction
| Late - >15s time lag in relation to contraction
48
Variable decelerations are associated with what complication of labour?
Cord compression/prolapse
49
What are the two types of variable decelerations?
Typical - U or V shaped, quick to recover (less sinister)
| Atypical - last >60 seconds, slow recovery (more sinister - associated with distress)
50
What does a sinusoidal pattern with little variability on the CTG indicate?
Significant foetal anaemia
| Short spells - foetal physiological behaviour such as thumb sucking
51
What is the most common indication for induction of labour?
Prolonged pregnancy
| Then, utero-placental insufficiency, pre-eclampsia, PROM
52
What total Bishop score is strongly predictive of spontaneous labour?
>8
53
What are the stages of induction of labour?
Cervical ripening
Artificial rupture of membranes
Cervical dilatation
54
In induction of labour, how is cervical ripening brought about?
Vaginal PGE2
55
Amniotomy is used as an adjunct to the vaginal PGE2, and releases local PGs to commence cervical ripening and myometrial contractions. What is the next step if there are no painful contractions 2 hours post amniotomy?
Oxytocin infusion
56
What are five complications of inducing labour?
```
Uterine hyperstimulation and rupture
Caesarian section
Atonic PPH
Intrauterine infection
Perineal damage from rapid/uncontrolled delivery
```
57
What is a side effect of oxytocin administration?
Uterine hyperstimulation
58
What are the consequences of uterine hyperstimulation?
Decreased uterine blood flow leads to foetal asphyxia
| Uterine tetany = continuous contraction.
59
What is a risk factor of uterine rupture?
Grand multipara
60
Why is it necessary to decrease the rate of oxytocin infusion as the rate of (induced) labour progresses?
Myometrium gets increasingly sensitive to oxytocin
| Risk of uterine hyperstimulation
61
When is labour premature?
Delivery from 24+0 weeks to 36+6 weeks
62
What are the causes of premature labour?
PROM
Idiopathic
Other - poor social conditions, APH, infection, severe maternal illness, extremes of maternal age
63
How does genital tract infection cause premature labour?
Promotes myometrial activity
Causes PROM from chorioamnioitis
Can penetrate the mucous plug, produce proteases, and destroy tissue
64
How can you assess risk of premature labour?
Presence of foetal fibronectin on the cervix - 20% women deliver
65
What factors are used to decide if tocolysis should be used in premature labour?
```
Age of gestation
Absence of infection/bleeding
Whether membranes are intact
Whether cervix is dilated
Availability of neonatal care
```
66
What is the first line tocolytic drug in premature labour?
```
Nifedipine
If CI (PPROM), then atosiban
```
67
Why do you give corticosteroids, and magnesium sulphate to a woman in premature labour?
Steroids: matures the foetal lung so decreases the risk of respiratory disease due to lack of surfactant.
MgSO4: neuroprotection: decreases risk of cerebral palsy
68
What are the signs of preterm prelabour rupture of membranes?
Sudden gush of fluid/constant leaking of fluid from the vagina
69
What are the causes of PPROM?
Infection
Polyhydramnios
Multiple pregnancy
Idiopathic
70
What is the management of PPROM?
Refer to hospital and admit for first 48h
Decide delivery or expectant management
Swab vaginal fluid and monitor for sepsis, prophylactic erythromycin 250mg QDS, corticosteroids
If evidence of infection - induce labour
No sex
Report any change in foetal movements and discharge
71
What percentage of women with PROM labour within 24 hours?
60%, but most women deliver spontaneously within 48 hours
72
What is the management of women with PPROM and Group B strep isolation?
Penicillin or clindamycin
73
What is prolonged pregnancy?
Any pregnancy that exceeds 42 weeks gestation from the first day of LMP in a woman with regular 28 day cycles
74
What are the foetal risks of prolonged pregnancy?
Meconium aspiration
Oligohydramnios
Macrosomia and shoulder dystocia
Cephalohaematoma
75
What are the maternal risks of prolonged pregnancy?
Increased risk of intervention (induction, use of instruments etc)
Increased risk of genital tract trauma
76
What is the management of prolonged pregnancy?
Stretch and sweep at 41 weeks
Induce labour 41-42 weeks
Daily CTGs after 42 weeks
Report any change in foetal movements
77
What causes the symptoms of foetal post-maturity syndrome?
Intrauterine malnutrition
78
What are the signs of foetal post maturity syndrome?
Scaphoid abdomen, peeling skin, little SC fat on body or limbs, overgrown nails, alert, anxious look, skin stained with meconium
79
What are the four categories of Caesarian section?
Elective, scheduled, urgent, immediate
80
How is a CS carried out?
Transverse incision in the lower uterine segment
81
What are the complications of CS?
Blood loss, infection, bladder/ureteral/bowel injury, endometritis, UTI, pulmonary atelectasis
82
What are the risks of vaginal birth after CS?
Uterine rupture
| Intrapartum death
83
What are the indications for instrumental delivery?
Maternal exhaustion
Prolonged 2nd stage/failure to progress
Foetal compromise
84
What are the adverse effects of use of forceps?
Maternal genital tract trauma
| Foetal injuries more rare - facial nerve palsy, skull fractures, ICH
85
What are the adverse effects of ventouse use?
Scalp lacerations and convulsions
Retinal/subgleal haemorrhage
ICH
86
When do you abandon instrumental delivery for CS?
No progressive descent with each pull (usually 3 pulls)
87
What are the indications for episiotomy?
Complicated vaginal delivery e.g. breech, shoulder dystocia
Extensive lower genital tract scarring
Foetal distress
Indication that there will be perineal trauma - button holing
88
What are the complications of episiotomy?
Bleeding, pain, scarring, infection, dyspareunia, fistula
89
What do third and fourth degree tears involve?
3rd - anal sphincter complex
| 4th - anal/rectal epithelium
90
What is the management of perineal tears?
Rapid repair
Broad spectrum antibiotics
Stool softeners
Refer if >6 weeks incontinence
91
What are the side effects of Entonox (NO and O2)?
Nausea, vomiting, feeling faint
92
Give one advantage and one disadvantage of epidurals
Adv - decreased maternal secretion of catecholamines, can be topped up
Disadv - Decreased maternal mobility, patchy block, nerve damage risk
93
Give three other methods of pain relief in labour (other than epidurals)
Pethidine - neonatal resp depression - nalaxone
Diamorphine - neonatal resp depression - naloxone
Meptazinol
Nitrous oxide
Spinal/CSE
94
What anaesthetic technique is most commonly used in CS?
Spinal
95
What anaesthetic is used in a spinal?
Hyperbaric bupivacaine usually with fentanyl
96
Where is the spinal anaesthetic injected?
Sub arachnoid space
97
What is the main advantage of a combined spinal and epidural anaesthesia (CSE)?
Spinal - rapid onset of a predictable block
| Epidural - can be topped up
98
Why may hypotension occur with a spinal anaesthetic and how is this combatted?
Sympathetic blockade
| IV fluids and ephedrine (vasopressor)
99
What's the best way of estimating the gestational age of a pregnancy?
First trimester ultrasound at 12/40, crown-rump-length (CRL)
100
What are the risks of footling breech presentation?
Chorioamnioitis
| Cord prolapse
101
At what gestational age is Anti-D prophylaxis given if the mother is Rhesus negative?
28 and 34 weeks
102
At what gestational age is an OGTT undertaken?
24-28 weeks
103
What uterine relaxants are given before ECV?
Terbutaline, salbutamol
104
What are the three stages of induction of labour?
Cervical ripening
Artificial rupture of membranes
Cervical dilatation
105
What are the risks of breech presentation?
Cord prolapse
Difficulty delivering head
Foetal hypoxia
106
What does the quadruple test test for?
hCG
AFP
Unconjugated oestriol
Inhibin A
107
What does the combined screening test test for?
Bloods - hCG and pregnancy-associated protein A (PAPP-A)
| Nuchal translucency
108
What are the contraindications to ECV?
Under 37 weeks preterm
Previous CS
Multiple pregnancy
PP
109
What are the four main indications for induction of labour?
Post-dates
Pre-labour rupture of membranes
Pre-eclampsia
Plus diabetes
110
What is the first sign of scar dehiscence in VBAC?
Abnormal CTG
111
What gives the best chance of VBAC?
Natural labour
112
What medication is used in uterine hyperstimulation?
Terbutaline
113
Detail the management of IUGR
Confirm dates
Ultrasound - symmetry and amniotic fluid volume
Doppler studies for placental function
114
What is a risk factor for pre-term labour?
Multiple pregnancy - stretch of myometrium and membranes
| Ascending infection
115
How is pre-term labour prevented in those with a history?
Cervical stitch
| Progesterone
116
What is bleeding at <24 weeks known as?
Threatened miscarriage
117
What are three uterine causes of APH?
Placenta abruption
Placenta praevia/vasa praevia
Marginal bleed (bleed from placental edge)
118
What are three cervical causes of APH?
Show - loss of mucous plug
Cervical cancer
Cervical polyp or ectropion
119
What causes the woody hard uterus in placental abruption?
Infiltration of blood into myometrium
120
What is placental migration?
Growth of the lower segment of the uterus after 20 weeks causes movement upwards of a placenta praevia at 32w
121
When is CS advised in major placenta praevias?
38 weeks
122
What is vasa praevia?
Placental vessels run over cervical os in the membranes
123
What are the consequences of vasa praevia?
Labour or ROM may result in catastrophic foetal exsanguination
124
What antibiotics are used for GBS prophylaxis and treatment of sepsis in the neonate?
Benzylpenicillin
Penicillin and clindamycin
125
What is the Bishop's score?
Pre-labour scoring score in predicting whether induction of labour will be required
126
What are the components of Bishop score?
```
Cervical dilatation (cm)
Cervical effacement (%)
Cervical consistency
Cervical position
Foetal station
```
127
What indicates amniotic fluid embolism?
Sudden collapse after ARM
Hypotension, tachycardia, MI
Shivering, sweating
128
What are the doses of corticosteroids and magnesium in premature labour?
24mg betamethasone/dexamethasone IM over 24-48h
4g IV MgSO4 bolus followed by infusion of 1g/hour over 24h
129
What are the indications for emergency cervical cerclage?
Women between 16+0 and 34+0 weeks who have a dilated cervix and exposed unruptured foetal membranes.
