Labour etc Flashcards
(112 cards)
1
Q
Features of a normal CTG trace
A
Base rate of 110-160bpm, variability of 5bpm, at least two accelerations (response to noise or movement) of >15bpm over a 20min period
2
Q
What intrapartum monitoring is usually done in low risk pregnancies
A
Intermittent auscultation with doppler or pinard stethoscope after contractions to check for decelerations
Every 15mins in stage 1 and every 5mins in stage 2
3
Q
Indications for FHR monitoring x7
A
High risk pregnancy
Use of oxytocin
Abnormality on IA (intermittent auscultation),
Fresh meconium passed, Maternal pyrexia
Fresh bleeding in labour or Maternal request
4
Q
What to do if maternal hypercontractility
A
Terbutaline - tocolysis -0.25mg SC and stop oxytocin
5
Q
Fetal blood sampling- what is it for and interpretation of results
A
To check for fetal hypoxia in presence of pathological FHR trace
pH >7.25 is normal - repeat in 1hr if FHR remains pathological
If 7.21-7.24 borderline therefore repeat in 30min
If less than 7.20 then deliver
6
Q
When is fetal blood sampling contraindicated? x3
A
Maternal infection - HIV, hepatitis, herpes
Suspected fetal clotting disorder
7
Q
What may loss of baseline variability of CTG suggest? x3
A
Preterm fetus is asleep, drug effects (diazepam, morphine) or hypoxia
8
Q
What may baseline tachycardia of CTG be associated with? x4
A
Maternal fever, b-sympathomimetic drug use, chorioamnionitis and acute/subacute hypoxia
9
Q
What do persistent fetal heart rates >200 bpm indicate?
A
Fetal cardiac arrhythmia
10
Q
Fetal baseline bradycardia indicates?
A
Heart rate less than 110 bpm rarely associated with fetal hypoxia (except in placental abruption) - may be increased fetal vagal tone, fetal heart block or cord compression (if spasmodic)
11
Q
Late decelerations on CTG
A
If develop 30seconds after end of contraction = fetal hypoxia
Degree and duration reflect severity
12
Q
When is crown-rump length measured and what are measurements expected to be?
A
6-12 weeks
10mm at 7 weeks
55mm at 12 weeks
13
Q
When can biparietal diameter and femur length be measures?
A
Biparietal diameter from 12 weeks
Femur length from 14 weeks
14
Q
When are biparietal diameter measurements most reliable?
A
Up to 20 weeks
Unreliable from 34 weeks
15
Q
On USS what is taken to indicate fetal chronic asphyxia?
A
Reduction in amniotic fluid demonstrated by pockets of fluid
16
Q
Definition of a premature infant
A
Born before 37+6 weeks
17
Q
Prevalence of prematurity in singletons, twins and triplets
A
6% of singletons
46% of twins
79% of triplets and more
18
Q
% of prematurity which is before 32weeks - when neonatal problems are greatest
A
1.4%
19
Q
What cause nitrazine sticks to go black
A
Liquor from ROM
Or false +ve with infected vaginal discharge, semen, blood or urine
20
Q
In what % does PROM initiate labour?
A
80%
21
Q
How should you manage PROM?
A
Give corticosteroids
IV antibiotics
Expedite labour
22
Q
Risk of intrauterine infection with PROM at 48, 72 and >72hour
A
10% by 48hour, 26% by 72hour, 40% >72hour
23
Q
What % of contractions cease spontaneously with premature labour?
A
50%
24
Q
Other management of premature labour
A
Give corticosteroids
Treat the cause if there is one
Possibly attempt to suppress contractions with tocolytics (unlikely to work if PROM or dilated >4cm)
25
Absolute CI for tocolytics with preterm labour x3
Chorioamnioitis
Fetal death or lethal abnormality
Condition needing immediate delivery
26
Relative CI for tocolytics with preterm labour
```
Fetal growth restriction or distress
Pre-eclampsia
Placenta praevia
Placental abruption
Cervix >4cm
B-sympathomimetics
```
27
Which is best tocolytic?
Nifedipine - use up to 48hours
28
Why are glucocorticoids given?
To help foetal surfactant production (mortality reduced 31%) and reduce complications of RDS by 44%
29
What is glucocorticoid regimen?
Betamethasone 12mg IM with 2nd dose 12-24hr later
30
When are glucocorticoids given?
All women at risk of preterm birth 24+0 - 34+6 weeks
Growth restriction
Before all elective c-sections up to 38+6weeks
Consider using at 35-6 weeks if delivery expedited for pre-eclampsia
31
Why is magnesium sulphate given?
Neuroprotective effect for babies
32
What is the definition of a growth restricted neonate?
Neonates weighing less than 10th centile for their gestational age
33
Maternal risk factors for IUGR x11
```
Multiple pregnancy
Malformation
Infection
Smoking
Diabetes
HTN
Anaemia
Pre-eclampsia
Renal disease
Heart disease
Asthma
```
34
What is cause of 10% of SGA
Women who only ever small babies
35
What causes asymmetric growth restriction?
Placental insufficiency - head will be larger proportionally - because fetus was starved
36
Amount of IUGR detected in utero
50%
37
Other than IUGR what are two other indicators of placental insufficiency
Oligohydramnios and poor fetal movements
38
How do you measure IUGR
Head and abdominal circumference
39
What indicates better outcome for IUGR
Good umbilical cord doppler flow
40
What should you give mothers with poor doppler flow
Aspirin low dose 75mg PO/24hr
41
IUGR after they're born x5
Keep warm as can't do temperature regulation
Incubator for smaller than 2kg
Hypoxia in utero causes high Hb at birth and therefore jaundice
Little stored glycogen therefore hypoglycaemia probe
More susceptible to infection
42
How do you distinguish premature from IUGR x8
Before 34 weeks there is no breast bud tissue then develops from 1mm diameter/week
Ear cartilage grows from 35-39 weeks therefore if fold back before this it won't spring back
Testes in inguinal canal at 35 weeks and scrotum in 37 weeks
Labia menora exposed in premature girls
Skin creases on ant. 1/3 foot sole appear by 35 weeks (on ant. 2/3 by 39weeks and everywhere after 39 weeks)
Prems have red hairy skin
Vernix made from 28 weeks and max at 36 weeks
Prems do not lie with leg flexed until 32 weeks - all limbs flexed by 36 weeks
43
Effects of IUGR in later life
```
by 23 mild cognitive problems have been overcome but still problems with:
HTN
T2DM
CAD
Autoimmune thyroid disease
```
44
Definition of large for gestational age babies
Above 90% centile for gestational age
45
Causes of large for gestational age
Constiutionally large,
Maternal diabetes
Hyperinsulinism
Beckwith-Wiedermann syndrome
46
Problems with LGA babies after birth x5
Large babies are prone to immaturity of suckling and swallowing - need temporary tube feeding
Large babies risk birth injury
Prone to hypoglycaemia and hypocalcaemia
Polycythaemia may result in jaundice
Prone to left colon syndrome - self-limiting condition clinically mimicking Hirschsprungs disease - temporary bowel obstruction
47
What is post-maturity defined as?
Prolonged pregnancy exceeding 42 completed weeks of pregnancy
48
Incidence of post-maturity
5-10% of pregnancies
49
Problems caused by prolonged pregnancy x6
```
Possible placental insufficiency
Larger fetuses
Skull more ossified therefore less mouldable
Increased meconium passage in labour
Increased fetal distress in labour
Increased c-section rates
```
50
What is done to prevent postmaturity
Induce at 41 weeks - either by manual sweep or induction
51
How is membrane sweep done? When is it offered?
Membrane sweep of fingers by placing finger through cervix
Thought to induce natural prostaglandins
May cause discomfort and a little bleeding
At 40-41 weeks in nullips and 41 weeks in multips
52
How and when do you do induction?
Offer after 41 completed weeks - vaginal prostaglandins followed by oxytocin
53
What do you do if mother declines induction?
Twice weekly CTG and ultrasound estimation of amniotic fluid depth to try to detect fetuses who may be becoming hypoxic
54
What does prolonged or repeated hypoxia lead to?
Fetal acidosis
55
What is an early sign of fetal hypoxia and later/other signs?
Passing of meconium in labour
Tachycardia persisting above 160bpm
Loss of variability of baseline of heart beat
56
Causes of obstetric shock? x7
```
Severe haemorrhage
Ruptured uterus
Inverted uterus
Amniotic fluid embolus
Pulmonary embolism
Septicaemia
Adrenal haemorrhage
```
57
What is the definition of antepartum haemorrhage? Prevelance
Vaginal bleeding after 24weeks
| Complicates 3-5% of pregnancies
58
What should you avoid with APH?
Vaginal exam because placenta praevia can bleed a lot
59
Dangerous causes of APH? x3
Placental abruption, placenta praevia, vasa praevia
60
Other uterine causes of APH? x2
Circumvallate placenta
| Placental sinuses
61
Lower genital tract causes of APH? x5
```
Cervical polyps
Erosions and carcinoma
Cervicitis
Vaginitis
Vulval varicosities
```
62
What is placental abruption?
Part of placenta becomes detached from uterus
63
Associations of placental abruption? x13
```
Pre-eclampsia
Smoking
Cocaine and methamphetamine use
Infection
Multiple pregnancies
IUGR
PROM
Polyhydramnios
Older maternal age
Thrombophilia
Abdo trauma
Assisted reproduction
Non-vertex presentation
```
64
Consequences of placental abruption
May cause fetal anoxia and death
Tenderness which may prevent good contraction in labour - beware of PPH
Uterine hypercontractility >7 in 15mins
Thromboplastin released may cause DIC - 10%
65
Presentation of posterior abruption
Backache
66
Abruption vs placenta praevia - concordance of shock and blood loss
Abruption - shock out of keeping with blood loss
| PP - Shock in proportion to visible loss
67
Abruption vs placenta praevia - pain and tenderness
Abruption - pain constant and tender uterus
| PP - no pain or tenderness
68
Abruption vs placenta praevia - fetal heart
Abruption - fetal heart absent/distressed
| PP - Fetal heart usually normal
69
Abruption vs placenta praevia - coagulation
Abruption - coagulation a problem
| PP - coagulation not a problem
70
Management of APH
```
Admit
IVI
O2 if shock
Blood transfusion
Catheterise and keep urine output >30ml/h
If severe - deliver - c-section if PP
```
71
What are Braxton-Hicks contractions?
Non-painful practice contractions
| Commonest after 36 weeks
72
What % of births are normal and need no intervention?
60%
73
When does normal labour occur and how
After 37 weeks
| Within 24hours of onset of regular spontaneous contractions
74
What happens in the latent phase of the first stage of labour x3
Painful contractions which are not necessarily continuous
Cervix initially effaces (shorter and softer)
Cervix then dilates to 4cm
75
What happens in the established phase of 1st stage of labour?
Contractions with dilatation from 4cm
76
How long does 1st stage of labour usually take in primip and multip?
8-18hr in primip
| 5-12h in multip
77
What is satisfactory rate of dilatation from 4cm?
0.5cm/hour
78
What monitoring do you need to do during first stage of labour? x6
Measure BP, temp 4-hourly
Pulse hourly
Assess contractions every 30mins (strength and frequency)
Measure frequency of bladder emptying
Offer PV exam every 4hours - to asses cervix dilatation, presentation of head
If not continuously monitored then assess fetal heart rate every 15mins
79
What is ideal contraction frequency, duration and strength
Strength - should not be able to indent uterus with finger during contraction
Frequency - 3-4 every 10mins, lasting up to 1min
80
What is the passive stage of 2nd stage of labour?
Complete dilatation but no desire to push
81
What is active stage of 2nd stage of labour?
Complete dilatation, baby can be seen, expulsive contractions, and maternal effort until baby is born
82
Monitoring during 2nd stage of labour? x5
```
BP and pulse hourly
Temp 4-hourly
Contractions 1/2 hourly
Auscultate for 1min after contraction every 5mins
PV exam hourly
```
83
How soon after start of 2nd stage would you expect birth in primip and multip?
Within 3hr in primip
| 2hr with multip
84
When should you cut cord?
1-min delay in vigorous term babies
| 3-min delay in premature babies
85
What is the 3rd stage of labour?
Delivery of placenta
Uterus contracts so that placenta separates from uterus - it then buckles and a small amount of retroplacental haemorrhage aids its removal
86
What decreases time to 3rd stage after baby is delivered and decreases PPH?
Syntometrine (ergometrine maleate + oxytocin) as the anterior shoulder is born
87
When is syntometrine contraindicated?
Can precipitate MI
CI in pre-eclampsia, severe hypertension, severe liver or renal impairment, severe heart disease, familial hypercholesterolaemia
88
What is premature rupture of membranes at term?
When membranes rupture after 37 weeks but prior to the onset of labour
89
Prevalence of PROM at term
8-10% of pregnancies
90
Whats a common aetiological factor for PROM at term
Lower genital tract infection
91
What % of women with PROM at term go into spontaneous labour within 24hrs?
What do you do with the rest of them?
60%
| Remaining 40% should induce - vaginal prostaglandins preferred method
92
What is the risk with PROM at term?
Risk of serious infection is increased 1% instead of 0.5%
93
If don't induce PROM at term what should you do?
Measure temp 4-hourly and come in if fever or change in colour/smell of vaginal loss
Give full course of antibiotics to treat
Also report if change in fetal movements
94
What may increase risk of infection in PROM at term?
Sexual intercourse
95
What % of UK labours are induced artificially?
20%
96
What are 75% of inductions done because of? (x4)
| And remaining 25% (x5)
HTN, pre-eclampsia, prolonged pregnancy, rhesus disease
Others due to diabetes, previous stillbirth, abruption, foetal death in utero, placental insufficiency
97
CI to induction of labour x8
```
Cephalopelvic disproportion
Pelvic tumour
Previous repair to cervix
Position other than face down
(Breech CI)
Cord presentation
Fetal distress
Placenta praevia
Vasa praevia
```
98
What % of women have a ripe cervix at term
95%
99
What is Modified Bishop Score?
Measure of cervical ripeness
100
How do you calculate modified bishop score?
```
Either 0, 1 or 2 points on each thing
Cervical dilatation (cm) = 0, 1-2 or 3-4
Length of cervix (cm) = >2, 1-2,
```
101
What score on Modified Bishop Score is ripe
>5
102
What do you do if cervix is not ripe?
Ripen it with prostaglandin vaginal gel (1mg) evening before or morning of induction
103
What do you do if failure to ripen? How often does this occur?
Repeat PGE2 6-8 hour later
| Happens in 12%
104
What do you do in induction of labour once cervix is ripe? (how do you induce)
Rupture the membranes (amniotomy)
Fetal heart rate monitoring
Oxytocin IV in 5% dextrose using pump
1-4 milliunits per min - increasing every 30mins until 3-4 contractions occur every 10mins
105
What do you do to induce labour if there has been intrauterine death?
Mifepristone and then prostaglandins or Misoprostol PV
106
What is definition of delay of 1st stage of labour
107
What should you do if delay in 1st stage of labour
Offer amniotomy (will
108
What do you do if there is still a delay in 1st stage of labour an hour after amniotomy is offered
Offer oxytocin if amniotomy done
| Offer amniotomy again if declined first time
109
When is oxytocin for augmentation dangerous
If multips as delay may be due to obstruction
110
What is definition of delay of second stage of labour?
If not delivered within 1hr of onset of 2nd stage in multips or 2hrs in primips
111
What do you do if delay of second stage of labour?
Offer amniotomy
| If stage 2 prolonged or fetal compromise then consider instrumental delivery or c-section
112
What does meconium in liquor at amniotomy mean?
Placental insufficiency
| If anything other than light staining in good liquor volume - fetal blood sampling indicated
