Obstetric Core Conditions Flashcards
1
Q
What is the lie of the fetus?
A
The lie describes the relationship of the fetus to the long axis of the uterus
2
Q
What is the presentation of the fetus?
A
The presentation refers to the part of the fetus that occupies the lower segment of the uterus or the pelvis
3
Q
What is abnormal lie?
A
When the fetus lie is either transverse or oblique (i.e. not parallel to the long axis of the uterus)
4
Q
`What is normal lie?
A
When the fetus lie is longitudinal
5
Q
What are the 2 types of fetal presentation in a longitudinal lie?
A
Cephalic and breech
6
Q
What is the aetiology of abnormal lie?
A
Circumstances which allow more room to turn or conditions that prevent turning or prevent engagement
7
Q
What conditions allow more room for the fetus to turn?
A
Polyhydramnios High parity (more lax uterus)
8
Q
What conditions prevent the fetus turning?
A
Uterine or fetal abnormalities
Twin pregnancies
9
Q
What conditions prevent engagement?
A
Placenta praevia
Pelvic tumours
Uterine deformities
10
Q
__________ is more commonly complicated by an abnormal lie than labour at full term
A
Preterm labour
11
Q
How common is abnormal lie?
A
1 in 200 births
12
Q
What is the management for abnormal lie in a woman under 37 weeks pregnant who is not in labour?
A
No action required
13
Q
What is the management for abnormal lie in a woman over 37 weeks pregnant?
A
Admit for US scan to identify a cause
14
Q
After 37 weeks, a woman with abnormal lie is often admitted to hopsital in case the ______________ and an ultrasound scan is performed to exclude particular causes, notable __________ and __________.
A
Membranes rupture; polyhydramnios; placenta praevia
15
Q
In the absence of pelvic obstruction, an abnormal lie will usually stabilise before how many weeks?
A
41 weeks
16
Q
What is a breech presentation?
A
Presentation of the buttocks
17
Q
How common is breech presentation?
A
Occurs in 3-4% of term pregnancies
18
Q
What are the 3 types of breech presentation?
A
Extended (70%)
Flexed (15%)
Footling (15%)
19
Q
What is the extended breech?
A
Both legs extended at the knee
20
Q
What is the flexed breech?
A
Both legs flexed at the knee
21
Q
What is the footling breech?
A
One or both feet present below the buttocks
22
Q
What is the aetiology of a breech presentation?
A
Idiopathic mostly Previous breech presentation Fetal and uterine abnormalities Twin pregnancies Placenta praevia Pelvic tumours Pelvic deformities
23
Q
Complications of abnormal lie
A
Labour cannot deliver fetus
Arm or umbilical cord prolapse when the membranes rupture
Uterine rupture if neglected
24
Q
What is the management of abnormal lie after 41 weeks, if the pelvis is obstructed or if the woman is in labour?
A
Elective caesarean
25
__________ is commonly associated with breech presentation.
Prematurity
26
What are the complications of breech presentation?
Increased perinatal mortality and morbidity due to congenital anomalies (long term neurological handicap) and intrapartum problems (hypoxia and birth trauma)
27
How is a breech presentation managed?
After 37 weeks, external cephalic version (ECV) is attempted
28
What is the success rate of ECV?
50% success rate
29
Contraindications for ECV
```
Antepartum haemorrhage
Ruptured membranes
Fetal compromise
Twins
Placenta praevia
```
30
What is the management of breech presentation if ECV has failed or is contraindicated?
Elective caesarean section slightly safer than a planned vaginal birth
31
Breech presentation is more common if __________ or a ___________
Preterm labour; previous breech presentation
32
What is the excess mortality in a breech presentation?
1%
33
What is an oblique fetal lie?
Head is in one iliac fossa
34
What is a transverse fetal lie?
Head is in the flank
35
Unstable lie in nulliparous women is ______ and usually signifies ________
Rare; obstruction
36
Why is ECV unjustified in managing an abnormal lie?
Fetus usually turns back
37
If ____________________________ occurs and persists for more than 48 hours, the mother is ________
Spontaneous cephalic version; discharged
38
Give an example of a uterine abnormality which could prevent fetal movement
Fibroids
39
Most common clinical feature of a breech presentation
Upper abdominal discomfort due to the hard head being palpable at the fundus
40
How is breech presentation diagnosis confirmed?
Ultrasound scan
41
What causes chicken pox?
Primary infection with herpes zoster virus
42
What is shingles?
Reactivation of a latent herpes zoster infection affecting adults in one or two dermatomes
43
How common is chicken pox in pregnancy?
0.03%
44
Chicken pox causes _____________________ in pregnancy
Severe maternal illness
45
How does a pregnant woman develop chicken pox?
If she is not immune to zoster, she can develop the infection after exposure to chicken pox or shingles
46
How common is teratogenicity in an early pregnancy chicken pox infection?
1-2%
47
Maternal infection in the 4 weeks preceding delivery can cause _____________
Severe neonatal infection
48
When is a severe neonatal chicken pox infection most common?
50% more common if delivery occurs within 5 days after or 2 days before maternal symptoms
49
How is a chicken pox infection treated during pregnancy?
Oral aciclovir
50
Pregnant women exposed to zoster are _____________
Tested for immunity
51
How is a chicken pox infection prevented in women who are non-immune?
IgG immunoglobulins given within 10 days of exposure
52
When are neonates given IgG immunoglobulins and closely monitored for chicken pox?
If neonate is delivered 5 days after or 2 days before maternal infection
53
How is chicken pox treated in a neonate?
Aciclovir
54
Infection is indicated in ___ of _____________ and is often ________
60%; preterm deliveries; subclinical
55
What is chorioamnionitis?
Infection of the fetus or placenta
56
Which bacteria is typically responsible for puerperal sepsis, and the most common bacterium associated with maternal death in the UK?
Group A streptococcus (Streptococcus pyogenes)
57
S. pyogenes is carried by how many people?
5-30%
58
What is the most common symptom of a S. pyogenes infection?
Sore throat
59
What are the clinical features of a S. pyogenes infection in pregnancy?
Chorioamnionitis with abdominal pain, diarrhoea and severe sepsis
60
What are the consequences of a S. pyogenes infection during pregnancy?
The fetus usually dies in utero and labour will then ensue
61
How is a S. pyogenes infection managed in pregnancy?
Early recognition, cultures and high dose antibiotics (and intensive care needed in severe cases)
62
How is S. pyogenes transmitted during pregnancy?
Maternal hand to perineal contamination (usually from children)
63
By what mechanism does chorioamnionitis cause preterm labour?
"The enemy knocks down the walls" (cervix is the wall)
64
What investigations should be done to identify chorioamnionitis?
Vaginal swabs - use sterile speculum if membranes ruptured
Maternal CRP raised
WCC raised on FBC (steroids also cause this to rise)
Lactate to assess severity of sepsis
CTG to asses fetal well-being
65
The presence of infection within the uterus is _____________ for the mother and _____________ for the neonate
Life threatening; worsens the outlook
66
How is chorioamnionitis treated?
IV antibiotics and immediate delivery, whatever the gestation
67
What are the clinical features of chorioamnionitis?
```
Contractions/abdo pain
Fever/hypothermia
Tachycardia
Uterine tenderness
Coloured/offensive liquor
Fetal tachycardia
(clinical signs often appear late)
```
68
Normal BP changes in pregnancy
Falls to a minimum in the second trimester by about 30/15 mmHg (rises to pre-pregnant levels by term)
69
How are hypertensive disorders in pregnancy classified?
Pregnancy induced hypertension or pre-existing/chronic hypertension
70
2 types of pregnancy induced hypertension
Pre-eclampsia
| Gestational hypertension
71
2 types of Pre-existing hypertension in pregnancy
Primary
| Secondary
72
Why does BP normally fall in pregnancy?
Reduced vascular resistance
73
What determines BP?
Systemic vascular resistance and cardiac output
74
What is pre-existing hypertension in pregnancy?
Diagnosed when the BP is already treated or exceeds 140/90 mmHg before 20 weeks gestation
75
How common is underlying hypertension in pregnancy?
Occurs in 5% of pregnancies
76
Risk factors for pre-existing hypertension in pregnancy
```
Old age
Obesity
Family history
Women who had hypertension after taking the COCP
Pregnancy induced hypertension
```
77
What is primary hypertension?
Idiopathic hypertension (most common)
78
What causes secondary hypertension?
```
Obesity
Diabetes
Renal disease (polycystic disease, renal artery stenosis or chronic pyelonephritis)
Phaeochromocytoma
Cushing's syndrome
Cardiac disease
Coarctation of the aorta
```
79
Patients with underlying hypertension are at a sixfold increased risk of ___________________
Superimposed pre-eclampsia
80
What can cause pre-existing proteinuria during pregnancy?
Renal disease
81
Clinical features of pre-existing hypertension
BP increases in late pregnancy
Symptoms often absent
Proteinuria often present in patients with renal disease
82
What needs to be excluded when examining for pre-existing hypertension?
Fundal changes
Renal bruits
Radiofemoral delay
83
Complications of pre-existing hypertension
Worsening hypertension
| Pre-eclampsia
84
Investigations for secondary hypertension
Two 24 hour urine collections for vanillylmandelic acid (VMA) to exclude phaeochromocytoma
85
What investigations need to be done for pre-existing hypertension?
Identify secondary hypertension
Look for coexistant disease
Identify pre-eclampsia
86
Investigations for co-existant disease with pre-existing hypertension
Renal function assessed
| Renal ultrasound
87
How is pre-eclampsia identified?
Assess for proteinuria and uric acid levels and compare later in pregnancy with at booking
88
Why does phaeochromocytoma need to be exlcuded?
High maternal mortality
89
How is pre-existing hypertension managed during pregnancy?
Labetalol 1st line
| Nifedpine 2nd line
90
Antihypertensives may not be required in the _____________ because of the _________________
2nd trimester; physiological fall in BP
91
Why are ACE inhibitors not used in pregnancy?
They are teratogenic and affect fetal urine production so must be changed before pregnancy
92
How is the risk of pre-eclampsia managed in pre-existing hypertension?
Lose dose aspirin
Screening using uterine artery doppler
Additional antenatal visits
93
What would indicate pre-eclampsia in a patient with pre-existing hypertension?
Worsening hypertension confirmed by significant proteinuria for the first time after 20 weeks
94
When is delivery usually undertaken in a patient with pre-existing hypertension?
38-40 weeks
95
What is a cord prolapse?
Occurs when, after the membranes have ruptured, the umbilical cord descends below the presenting part
96
What happens if a cord prolapse is untreated?
Cord is compressed or goes into spasm, and the baby becomes rapidly hypoxic
97
How often does cord prolapse occur?
1 in 500 deliveries
98
How is a cord prolapse diagnosed?
After identifying fetal distress, diagnosis made by a vaginal examination
99
Risk factors for a cord prolapse
```
Preterm labour
Breech presentation
Polyhydramnios
Abnormal lie
Twin pregnancies
```
100
More than half of cord prolapses occur at _____________________
Artificial amniotomy
101
How is a cord prolapse managed initially?
The presenting part must be prevented from pressing the cord (either examining finger pushes it up or terbutaline is given)
102
What is terbutaline?
A tocolytic
103
If the cord is out of the introitus, it should be __________ but not __________
Kept warm and moist; forced back inside
104
What should the patient be doing whilst preparations are being made for delivering a baby with a cord prolapse?
Patient should be on all fours
105
How is a baby usually delivered with a cord prolapse?
Immediate caesarean section
106
How is a baby delivered with a cord prolapse if the cervix is fully dilated and the head is low?
Instrumental vaginal delivery
107
What is the fetal mortality of cord prolapse?
Rare if promptly treated
108
What is cytomegalovirus (CMV)?
A herpesvirus transmitted by personal contact
109
How many women in the UK are immune to CMV?
35%
110
Up to ___ of women develop CMV infection, usually ________ in pregnancy
1%; subclinical
111
CMV is a common cause of child ________ and _________
Handicap; deafness
112
How often is CMV vertically transmitted to the fetus?
40% of the time
113
What percentage of infected neonates are symptomatic at birth?
10%
114
What are the symptoms of CMV infection in neonates?
```
IUGR
Pneumonia
Thrombocytopenia
Most develop severe neurological sequelae
Death
```
115
What severe neurological sequelae may a neonate develop if infected with CMV?
Hearing, visual and mental impairment
116
Asymptomatic neonates with CMV are at a ___ risk of _______
15%; deafness
117
Ultrasound abnormalities such as _________________ are evident in only ___ of CMV infections
Intracranial or hepatic calcification; 20%
118
How is a maternal CMV infection diagnosed?
Specifically requesting CMV testing
CMV IgM positive a long time after infection
Titres will rise
IgG avidity is low with recent infection
119
How is vertical transmission of CMV identified if maternal infection is confirmed?
Amniocentesis at least 6 weeks after maternal infection (and after 20+ weeks) will confirm or refute vertical transmission
120
How is CMV infection in pregnancy managed?
Close surveillance for US abnormalities to determine those at risk of neurological sequelae
No prenatal treatment
Termination offered
121
Why is routine screening for CMV infections not advised?
Most maternal infections do not result in neonatal sequelae and an amniocentesis involves risk
122
Is vaccination for CMV available?
No
123
Most neonates infected with CMV are ____________
Not seriously affected
124
Why does glucose tolerance decrease in pregnancy?
Altered carbohydrate metabolism and antagonistic effects of human placental lactogen, progesterone and cortisol
125
Why is pregnancy diabetogenic?
Women without diabetes but with impaired or potentially impaired glucose tolerance often deteriorate enough to classified as diabetic in pregnancy (gestational diabetes)
126
2 types of diabetes in pregnancy
Pre-existing, Type 1 (5%) or 2 (7.5%) or gestational diabetes (87.5%)
127
What percentage of pregnant women are affected by pre-existing diabetes?
1%
128
What are the maternal complications of pre-existing diabetes?
```
Increased insulin requirements by 300%
Hypoglycaemia
Worsening retinopathy
Pre-eclampsia and hypertension
UTIs
Wound/endometrial infections after delivery
Operative/instrumental delivery more likely
Rarely ketoacidosis
Worsening IHD
Diabetic nephropathy
```
129
What are the fetal complications of pre-existing diabetes?
Congenital abnormalities (neural tube or cardiac defects)
Preterm labour
Reduced fetal lung maturity
Macrosomia (leads to polyhydramnios and increased urine output)
Birth trauma, shoulder dystocia
Fetal compromise, distress or death
130
Why is diabetes a problem in pregnancy?
Even slightly increased Glucose levels have adverse pregnancy effects
131
The kidneys of non-pregnant women start to excrete glucose at a threshold of _______
11mmol/L
132
Why is urinalysis for glycosuria not a useful diagnostic test for diabetes in pregnancy?
Kidneys excretion threshold for glucose decreases in pregnancy, so glycosuria may occur at physiological blood glucose concentrations
133
What is macrosomia?
Excessive fetal growth
134
What causes macrosomia?
Raised fetal blood glucose induce fetal pancreatic islet cell hyperplasia leading to hyperinsulinaemia which causes fat deposition and excessive growth
135
What happens to insulin requirements in women with pre-existing diabetes during pregnancy?
Insulin requirements increase in order to maintain normoglycaemia
136
Why are women with gestational diabetes less affected by diabetic complications in pregnancy?
Complications are related to glucose levels, and women with gestational diabetes generally have better control
137
How is pre-existing diabetes managed?
Precise preconceptual glucose control
Fetal monitoring
Assessment of maternal complications
Consultant based antenatal care
Delivery in a unit with neonatal facilities
MDT approach (midwife, GP, obstetrician dietician)
Patient education
138
Preconceptual management of pre-existing diabetes
```
Optimal control of glucose levels
5mg folic acid given
Statins stopped
Antihypertensives substituted for labetalol or methyldopa
Assess renal function, BP and retinae
```
139
What is optimal preconceptual glucose control?
Monthly HbA1c <48
| Fasting glucose 4-7mmol/L
140
What drugs can help optimise glucose levels?
Insulin and metformin
141
How is renal function assessed?
Creatinine should be <120umol/L
142
How are glucose levels managed during pregnancy?
```
Metformin
Rapid acting insulin analogues
Doses progressively increased as pregnancy advances
Advice on exercise and diet
Glucagon
```
143
How are glucose levels monitored during pregnancy, and what should they be?
HbA1c checked at booking
Home glucometer - fortnightly contact with healthcare professional
Fasting <5.3mmol/L
1 hour after food <7.8mmol/L
144
How is insulin given for pre-existing diabetes in pregnancy?
Combination of once/twice daily long/intermediate acting with 3 preprandial short acting insulin injections
Fasting level should be >4mmol/L and glucagon is given
145
How are the complications of pre-existing diabetes in pregnancy monitored?
Renal function checked
Retinae screened for retinopathy
(Repeated each trimester if any abnormal)
146
How is the risk of pre-eclampsia in pre-existing diabetes managed?
75mg aspirin daily from 12 weeks
147
How is diabetic ketoacidosis managed in pregnancy?
ABCDE emergency approach
148
How is the fetus monitored if the mother has pre-existing diabetes?
Fetal echocardiography indicated
| Growth scans at 32 and 36 weeks
149
When is delivery advised for women with pre-existing diabetes?
37-39 weeks
150
Elective caesarean is often used where the estimated fetal weight exceeds _____
4kg
151
Why does the neonate commonly develop hypoglycaemia if the mother had pre-existing diabetes?
Fetus has become accustomed to hyperglycaemia and has high insulin levels
152
What problems may arise in the neonate if the mother had pre-existing diabetes during her pregnancy?
Neonatal hypoglycaemia
| Respiratory distress syndrome
153
____________ is strongly advised in women with pre-existing diabetes
Breast feeding
154
Neonatal blood glucose should be checked within _____ of birth
4 hours
155
What can diabetic nephropathy lead to in pregnancy?
Massive proteinuria and deterioration in maternal renal function
156
The mother's dose of insulin can be ______________
Rapidly changed to pre-pregnancy levels after delivery
157
What is eclampsia?
The occurrence of epileptiform (grand mal) seizures often as a drastic complication of pre-eclampsia
158
Maternal complications of pre-eclampsia
```
Eclampsia
Cerebrovascular haemorrhage
HELLP syndrome
Renal failure
Pulmonary oedema
```
159
The occurrence of any complications of pre-eclampsia is an indication for __________
Delivery whatever the gestation
160
How often does eclampsia occur?
0.03% of all pregnancies in UK
161
What causes eclampsia?
Cerebrovascular vasospasm
162
How does eclampsia cause mortality?
Hypoxia and concomitant complications of severe disease
163
How is eclampsia treated?
Magnesium sulphate and intensive surveillance for other complications
164
What are the causes of epileptiform seizures in pregnancy?
Maternal epilepsy
Eclampsia
Hypoxia from any cause
165
Magnesium sulphate is not useful for ______________
Non-eclamptic seizures
166
How are non-eclamptic seizures managed?
Airway cleared
O2 given
CPR if required
Diazepam normally stops seizure
167
______________ is superior to ___________ in the eclamptic woman
Magnesium sulphate; diazepam
168
Epilepsy affects ____ of pregnant women
0.5%
169
Seizure control can deteriorate in _________, particularly in _______
Pregnancy; labour
170
Why should antiepileptic treatment be continued during pregnancy?
Epilepsy is a significant cause of maternal death
171
The risk of ___________ is increased by ____ in maternal epilepsy
Neural tube defects; 4%
172
Why is the risk of congenital abnormalities such as NTDs increased in epilepsy?
Largely due to drug therapy
173
What is the risk of a newborn having epilepsy if its mother has it?
3%
174
The risks of NTDs in epilepsy are ____________, higher with ___________ and higher with certain drugs (e.g. __________)
Dose dependent; multiple drug usage; sodium valproate
175
How is epilepsy managed in pregnancy?
Preconceptual assessment - swap to non-teratogenic drugs
Seizure control with as few drugs as possible at the lowest dose
5mg daily folic acid (high dose)
176
Why should sodium valproate be avoided in pregnancy?
Associated with a higher rate of congenital abnormalities and with lower intelligence in children
177
All women of reproductive age with epilepsy are best managed as if __________________________
They are contemplating pregnancy
178
Which antiepileptics are safest in pregnancy?
Carbamazepine and lamotrigine
179
__________ and __________ plasma levels fall in pregnancy so __________ are commonly required
Lamotrigine; levetiracetam; dose increases
180
From 36 weeks, _____________ is given orally for women on enzyme inducing antieplipetics
10mg Vitamin K
181
How are fetal abnormalities excluded in epileptic women?
20 week scan and fetal echocardiography
182
What is slow labour?
Progress slower than 0.5cm/hour after 4cm (the latent phase)
183
What is prolonged labour?
>12 hour duration after the latent phase
184
Slow progress in labour is common in ___________ bur rare in _____________
Nulliparous women; multiparous women
185
How does the 'powers' contribute to slow progress in labour?
Inefficient uterine action
186
How does the 'passenger' contribute to slow progress in labour?
Fetal size
Disorders of rotation
Disorders of flexion
187
Disorders of rotation
Occipito-transverse position
| Occipito-posterior position
188
Disorder of flexion
Brow presentation
| Face presentation
189
How does the 'passage' contribute to slow progress in labour?
Cephalo-pelvic disproportion
| Rarely cervical resistance
190
General management for slow progress in labour
Wait if natural labour is wanted
Mobilise
Improve support
191
Management for slow progress in labour for nulliparous women
Amniotomy
| Oxytocin
192
Management for slow progress in labour for multiparous women
Amniotomy
| Oxytocin if malpresentation/malposition excluded
193
What is the management for slow progress in the first stage of labour if all else fails?
Caesarean section
194
What is the management for slow progress in the second stage of labour if all else fails?
Instrumental delivery
195
What is fetal distress?
An acute situation such as hypoxia that may result in fetal damage or death if it is not reversed or if the fetus is delivered urgently
196
What is occipito-posterior position?
Abnormality of rotation, with the face upwards (some extension is common)
197
How often does the OP position occur?
5% of deliveries
198
When is OP position more common?
Early labour
199
What is the aetiology of the OP position?
Idiopathic
Inefficient uterine action
Pelvic variants
200
What are the features of OP position?
Slow labour
Back pain
Early desire to push
Occiput posterior on vaginal examination
201
Management of OP position if progress is normal
Nil
202
Management of OP position if slow progress
Amniotomy and oxytocin (cautious if multiparous)
C-section if these fail in 1st stage
Rotational instrumental delivery if these fail in 2nd stage (and >1-2h of pushing)
203
Causes of permanent fetal damage attributable to labour
```
Fetal distress/hypoxia
Infection e.g. group B strep
Meconium aspiration leading to chemical pneumonitis
Trauma e.g. forceps
Fetal blood loss
```
204
____ of cerebral palsy cases are attributed solely to intrapartum problems
10%
205
What indicates significant fetal hypoxia?
pH of <7.20 in fetal scalp (capillary) blood or ominous fetal heart rate abnormalities
206
At what fetal capillary pH is neurological damage considerably more common?
<7.00
207
What is the aetiology of fetal distress?
Contractions temporarily reduce placental perfusion and may compress the umbilical cord
So longer labours and excessive time spent pushing (>1 hour) more likely to produce hypoxia
208
What can cause acute hypoxia in labour?
```
Placental abruption
Hypertonic uterine states
Oxytocin
Prolapse of umbilical cord
Maternal hypotension
```
209
Intrapartum risk factors for fetal distress
Long labour
Meconium
Epidural or oxytocin use
Maternal fever
210
Antepartum risk factors for fetal distress
Pre-eclampsia
Diabetes
IUGR
211
Fetuses with risk factors for fetal distress are usually ________________________
Monitored in labour with CTG
212
How is fetal distress diagnosed/detected?
```
Colour of the liquor - meconium
Fetal HR auscultation
Cardiotocography (CTG)
Fetal ECG
Fetal blood (scalp) sampling
```
213
Level 1 screening for fetal distress
Intermittent auscultation of fetal heart. If it is abnormal, or meconium inspected, or a long or high risk labour proceed to level 2
214
Level 2 screening for fetal dstress
Continuous CTG. If sustained bradycardia >5min, deliver.
| If abnormal on other criteria, proceed to level 3.
215
Level 3 screening for fetal distress
Fetal blood sampling. If abnormal proceed to level 4
216
Level 4 screening for fetal distress
Delivery by quickest route (C-section if 1st stage, Instrumental vaginal if 2nd stage)
217
Normal features of a CTG
Rate 110-160
Accelerations
Variability >5bpm
218
Abnormal features of a CTG
Tachy or bradycardias
Decelerations
Reduced variability
219
Indications for a CTG
Prelabour risk factors - pre-eclampsia, IUGR, previous C-section, induction
In labour risk factors - meconium, oxytocin use, temp >38C, during epidural analgesia
Intermittent auscultation abnormalities
220
Management of fetal distress
In utero resuscitation
| If this fails, fetal blood sampling (delivery if pH <7.20)
221
How is in utero resuscitation performed?
```
Place woman in left lateral position to avoid aortocaval compression
O2 and IV fluids given
Oxytocin stopped
Stop contractions using terbutaline
Vaginal exam to exclude cord prolapse
```
222
Mechanism of action of terbutaline
Beta 2 agonist
223
When is immediate delivery expedited?
FBS pH <7.20
| CTG shows sustained bradycardia
224
What is small for gestational age (SGA)?
The weight of the fetus is less than the tenth centile for its gestation (2.7kg at term)
225
What is intrauterine growth restriction (IUGR)?
Fetus is small compared to its genetic potential and is compromised
226
Aetiology of SGA
Asian ethnicity
Nulliparity
Female fetal gender
Low maternal weight and height
227
Aetiology of IUGR
```
Maternal illness (renal disease, pre-eclampsia)
Multiple pregnancy
Chromosomal abnormalities
Infections (CMV)
Smoking, drug use
Malnutrition
```
228
Clinical features of IUGR
Low symphysis-fundal height
| Features of pre-eclampsia (check BP and urine for proteinuria)
229
How is SGA/IUGR invetsigated?
US scan
Fetal anomaly scan
Check CMV status
Chromosomal abnormalities via amniocentesis
Umbilical artery doppler (umbA) if <34 weeks
UmbA and middle cerebral artery doppler (for cerebroplacental ratio) if >34 weeks
CTG if dopplers severely abnormal (e.g. AEDF)
230
Management of SGA <37 weeks
Monitor growth with US every 2-3 weeks
231
Management of SGA >37 weeks
No intervention if growth is consistent and umbA normal
| Consider delivery
232
Management of IUGR <34 weeks
Twice weekly umbA doppler if they are abnormal (but no absent end diastolic flow - AEDF)
Admission and steroids if AEDF
Daily CTG if AEDF <32 weeks
Deliver by C-section if umbA shows AEDF >32 weeks or if CTG abnormal
Give magnesium sulphate just prior to delivery
233
Management of IUGR >34 weeks
Monitor CPR
Consider delivery
Induce delivery by 37 weeks
234
What is fetal compromise?
A chronic situation when conditions for the normal growth and neurological development are not optimal, commonly causing IUGR
235
Causes of fetal compromise
Poor nutrient transfer via the placenta (placental dysfunction)
236
IUGR is a major cause of ________
Stillbirth
237
Complications of IUGR
```
Stillbirth
Fetal distress in labour
Neonatal unit admission
Long term handicap
Preterm delivery
Maternal risks (due to pre-eclampsia or caesarean)
```
238
Why is reduced fetal movements not a consistent feature of IUGR?
A compromised fetus only stops moving when very unwell
239
_________ commonly co-exists with IUGR
Pre-eclampsia
240
Major risk factors for SGA at booking
```
Previous SGA or stillbirth
Heavy smoking
Cocaine use
Heavy daily exercise
Diabetes or other maternal illness
Parental SGA
```
241
A reduction in ___________ by 30% of the _______________ suggests IUGR
Growth velocity; abdominal cirucmference
242
What is oligohydramnios?
Reduced volume of amniotic fluid (sign of IUGR)
243
CTG becomes abnormal in IUGR only when _____________________
Severe compromise of fetal distress is present
244
What is gestational diabetes?
Carbohydrate intolerance diagnosed in pregnancy which may or may not resolve after pregnancy, causing glucose levels to rise temporarily to diabetic levels
245
Why is gestational diabetes becoming more common?
Increasing prevalence of obesity
246
What proportion of pregnant women develop gestational diabetes?
16%
247
How is gestational diabetes diagnosed?
Fasting glucose >5.6mmol/L
| Abnormal glucose tolerance test (GTT)
248
What is an abnormal glucose tolerance test?
Glucose >7.8mmol 2 hours after a 75g glucose load
249
Risk factors for gestational diabetes
```
Previous gestational diabetes
Previous fetus >4.5kg
Previous unexplained stillbirth
First degree relative with diabetes
BMI >30
South Asian, black Caribbean or Middle Eastern
Polyhydramnios
Persistent glycosuria
```
250
Risk based screening for gestational diabetes
GTT at 28 weeks if risk factors present
251
When is the GTT performed in women with previous gestational diabetes?
18 weeks
252
Initial treatment for gestational diabetes
Give glucometer
Advise diet and exercise
Check HbA1c for pre-existing diabetes
If fasting >7, treat with insulin as pre-existing diabetic
If fasting <7 but after 2 weeks levels >5.3 before meals or >7.8 1 hour after meals, treat with metformin
253
Antenatal care for gestational diabetes
Managed as for pre-existing diabetes
| If well controlled, delivery need not be before 41 weeks (induce at this point)
254
A fasting glucose should be measured _________ postpartum in women with gestational diabetes
6 weeks
255
More than ____ of women with gestational diabetes will become diabetic within the next 10 years
50%
256
What is gestational hypertension?
New hypertension after 20 weeks without proteinuria
257
Management for gestational hypertension
Monitor for fetal compromise
| Delivery by 40 weeks is usual
258
What criteria make up HELLP syndrome?
Haemolysis
Elevated Liver enzymes
Low platelets
259
Clinical features of haemolysis
Dark urine
Raised lactic dehydrogenase (LDH)
Anaemia
260
Clinical features of elevated liver enzymes
Epigastric pain
Liver failure
Abnormal clotting
261
Low platelets in HELLP syndrome is normally ___________
Self limiting
262
What is HELLP syndrome?
Liver and coagulation problems occurring as a complication of pre-eclampsia
263
What other features may occur with HELLP syndrome?
DIC
Liver failure
Liver rupture
Liver infarction or subcapsular haemorrhage
264
Treatment of HELLP syndrome
Supportive
Magnesium sulphate prophylaxis against eclampsia
Intensive care in severe cases
265
Investigations to diagnose HELLP syndrome
Rapid fall in platelets
Rise in LFTs (ALT) - liver damage
LDH levels rise
Rising creatinine (impaired renal function)
266
What causes a rapid fall in platelets in HELLP syndrome?
Platelet aggregation on damaged endothelium
267
What is induction of labour?
Labour started artificially
268
What is augmentation?
When contractions of established labour are strengthened
269
When is induction of labour performed?
Situations where allowing the pregnancy to continue would expose the fetus and/or the mother to risk greater than that of induction
270
What determines the whether or not induction is successful?
The state or favourability of the cervix
271
The lower the Bishop's score, the more ______________ the cervix is for induction
Unfavourable
272
How is the state of the cervix measured?
Bishop's score or transvaginal ultrasound
273
What components make up Bishop's score?
```
Consistency of cervix
Degree of effacement of cervix
Cervical dilatation
Station of the head
Cervical position (anterior or posterior)
```
274
What is the station of the fetal head?
How low in the pelvis the fetal head is
275
Medical methods of induction
Prostaglandin E2
| Oxytocin (after amniotomy/membrane rupture)
276
Surgical methods of induction
Amniotomy
277
How is PGE2 used to induce labour?
Gel or slow release preparation is inserted into the posterior vaginal fornix
278
When is PGE2 best used for induction?
Nulliparous women
| Most multiparous women (unless cervix is very favourable)
279
PGE2 either __________ or improves the _____________ to allow amniotomy
Starts labour; 'ripeness' of the cervix
280
How is amniotomy and oxytocin used to induce labour?
Forewaters are ruptured using an amnihook to artificially rupture membranes
Oxytocin infusion given within 2 hours if labour has not ensued
281
When is oxytocin used alone to induce labour?
If spontaneous rupture of the membranes has already occured
282
What is natural induction?
Cervical sweeping involves passing a finger through the cervix and 'stripping' between the membranes and the lower segment of the uterus
283
At 40 weeks, natural induction reduces the chance of __________ and ______________
Induction; postdates pregnancy
284
Fetal indications for induction of labour
```
Prolonged pregnancy
Suspected IUGR or compromise
Antepartum haemorrhage
Poor obstetric history
Prelabour term rupture of membranes
```
285
Materno-fetal indications for induction of labour
Pre-eclampsia
| Diabetes or hypertension
286
Maternal indications for induction of labour
Social reasons
| In utero death
287
Absolute contraindications for induction of labour
```
Acute fetal compromise (abnormal CTG)
Abnormal lie
Placenta praevia
Pelvic obstruction (mass or deformity)
Cephalo-pelvic disproportion
```
288
Relative contraindications for induction of abour
One previous caesarean section (scar rupture)
| Prematurity
289
Why is the fetus at an increased risk during induced labour?
Use of drugs
| Indication for induction
290
How is induced labour managed?
CTG monitoring
| Oxytocin needed in labour
291
Induction commonly increases the __________________
Time spent in early labour
292
Complications of induced labour
```
Inefficient uterine activity
Hyperstimulation
Postpartum haemorrhage
Intra/postpartum infection
Prematurity
Risk of instrumental delivery or caesarean
```
293
What is the consequence of inefficient uterine activity when inducing labour?
Labour may fail to start or be slow
294
What are the consequences of hyperstimulation when inducing labour?
Fetal distress
| Uterine rupture
295
What is the incidence of twins?
1.3%
296
What is the incidence of triplets?
0.1%
297
The incidence of twins is increasing due to _____________ and ____________
Fertility treatments; older mothers
298
What are dizygotic twins?
Different oocytes fertilized by different sperm
299
What are monozygotic twins?
Division of the zygote after fertilization by one sperm
300
What are dichorionic twins?
Two placentas and two amniotic sacs (can be dizygotic or monozygotic)
301
What are monochorionic twins?
Shared placenta (always monozygotic)
302
What proportion of twins are dichorionic?
70%
303
What are monochorionic diamniotic twins?
Identical twins (MZ) that share a placenta but not amniotic sac
304
What proportion of twins are monochorionic diamniotic?
30%
305
What are monochorionic monoamniotic twins?
Identical twins (MZ) that share a placenta and amniotic sac
306
What proportion of twins are monochorionic monoamniotic?
1%
307
Aetiology of multiple pregnancies
Ovulation induction and IVF
Genetic factors
Increasing age and parity
308
How are multiple pregnancies diagnosed?
US scan
Vomiting
Large for dates
More than 3 fetal poles
309
Maternal complications of multiple pregnancies
Pre-eclampsia
Anaemia
Gestational diabetes
Operative delivery
310
Fetal complications of multiple pregnancies
```
Increased morbidity and mortality
Miscarriage
Preterm labour
Placental insufficiency
IUGR
Ante/postpartum haemorrhage
Malpresentations
```
311
Fetal complications for monochorionic twins
Congenital abnormalities
Twin-twin transfusion (TTTS)
IUGR
312
Management for women with multiple pregnancies
```
Early diagnosis
Identification of chorionicity
Consultant care
Iron and folic acid supplements
Anomaly scan
Surveillance for pre-eclampsia, diabetes, anaemia
Serial US at 28, 32 and 36 weeks
```
313
Management for women with monochorionic twins
US fortnightly from 12 weeks for TTTS and IUGR
314
When are dichorionic twins delivered?
37 weeks
315
When are monochorionic twins delivered?
36 weeks
316
When is a caesarean indicated for twins?
If first twin is not cephalic
317
What monitoring is needed whilst delivering twins?
CTG
318
How is the second twin delivered?
Lie of second twin checked
ECV to longitudinal lie if necessary
Amniotomy when presenting part s engaged, then maternal pushing
319
When is a ventouse or breech extraction necessary for delivering twins?
If fetal distress
320
What is the incidence of twin-twin transfusion syndrome (TTTS)?
15% of all monochorionic twins
321
What is the pathology of TTTS?
Unequal blood distribution in a shared placenta leading to discordant blood volumes, liquor and growth
322
How is TTTS diagnosed?
Discordant liquor volumes
323
Clinical features of the recipient twin in TTTS
Larger twin
Polyhydramnios
Fluid overload
Heart failure
324
Clinical features of the donor twin in TTTS
Smaller twin
| Oligohydramnios
325
Complications of TTTS
Late miscarriage
Severe preterm delivery
In utero death
Neurological damage
326
How is TTTS managed?
US surveillance from 12 weeks
| Laser ablation if TTTS is diagnosed
327
What is the prognosis of untreated TTTS?
Very poor if untreated
328
What is the prognosis of TTTS with laser ablation?
50% both twins survive
| 80% one twin survives
