Obstetrics Flashcards

1
Q

What is the best way of estimating gestational age?

A

First trimester ultrasound at 12/40 weeks

Measuring the Crown Rump Length

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2
Q

Describe the pregnancy timeline:

A
Booking appointment 8-10 weeks
Dating scan 11-13 weeks
Anomaly scan 20 weeks
OGTT at 24-28 weeks - if needed
Anti-D prophylaxis 28 & 34 weeks - if negative
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3
Q

Describe the combined screening:

A

11 - 13 weeks - combines ultrasound and 2 blood test
- hCG
- PAPP-A (Pregnancy associated protein A)
Gives an early result and is 85% sensitive
2.2% Fasle positive

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4
Q

Describe the quadruple test:

A
14-20 weeks - uses 4 blood tests and maternal age 
- hCG
- alpha-fetoprotein (AFP)
- unconjugated oestriol 
- inhibin-A 
80% sensitive and 3.5% false positive
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5
Q

Explain the risk and options for a mother who has screened positive for the combined screening test:

A

Risk - explain percentage chance
1st option is to do nothing

Chorionic Villus Sampling: 11 -14 weeks
- 1 -2% chance of miscarriage

Amniocentesis: 15 weeks and onwards
- 0.5-1% chance of miscarriage

Non-invasive prenatal testing
- Blood test, Currently private

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6
Q

Explain the risks of a breech presentation during delivery:

A

Cord prolapse
Difficulty delivering the head
Fetal hypoxia
Increased foetal mortality and morbidity

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7
Q

Explain External Cephalic version

A

A method for turning a breech into a head down
May prevent a breech vaginal delivery or c-section
Uterine relaxants given before hand e.g. Terbutaline
CTG performed before and after
May require Anti-D
Risk - of foetal distress, cord entanglement
- Emergency c-section 1:200
Success rate 40% in nulliparous, 60% in multip

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8
Q

What are the possible causes of large for dates?

A

Wrong dates
Big baby
Polyhydramnios
Big baby & Polyhydramnios

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9
Q

Causes of polyhdramnios:

A

DITCH

Diabetes
Idiopathic
Twins - twin to twin 
Congenital abnormalities - VSD etc. 
Heart failure - anaemia - haemolysis
- causes increased naturitic peptides
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10
Q

Explain the risk of polyhydramnios:

A
Placental abruption
Pretty unusual lie
Premature labour
Prolapse of cord
Post partum haemorrhage
Perinatal mortality
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11
Q

What are the four main indications for induction:

A

Post dates
Pre-labour rupture of membranes
Pre-eclampsia
Plus diabetes

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12
Q

What are the three stages of Induction of labour:

A

Stretch and sweep

  1. Cervical ripening - Vaginal prostagladins
  2. Amniotomy - ARM
  3. Cervical dilation - IV Oxytocin
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13
Q

Explain stage one of induction of labour:

A

Cervical ripening

  • vaginal prostaglandin pessaries or gel
  • Softens and shortens cervix
  • Risk of hyperstimulation and fatal distress
  • Intermittent CTG monitoring required
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14
Q

Explain stage two of induction of labour:

A

Amniotomy

  • Once cervix is sufficiently effaced
  • an amnihook is used to rupture the membranes
  • Risk of cord prolapse if presenting part is high
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15
Q

What score is used to predict the likelihood of spontaneous labour?

A

Bishop score

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16
Q

Explain stage three of induction of labour:

A

Cervical dilatation

  • IV oxytocin used to generate contractions
  • Start on a low dose and titrate it up
  • To achieve 3-4 contractions every 10 minutes
  • Risk of uterine hyper stimulation
  • Continuous CTG monitoring
  • Progress is monitored on a partogram
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17
Q

What are the risk of diabetes in pregnancy?

A

SMASH

Shoulder dystocia
Macrosomina
Amniotic fluid excess
Still birth
Hypertension and neontal hypoglycaemia
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18
Q

What advice should be given to someone with pre existing diabetes who is wanting to get pregnant?

A

The impact of diabetes starts from pre-conception
Take high dose folic acid (5mg daily) from pre-conception
Don’t stop contraception until good control achieved
Avoid pregnancy if poor control
increases risk of congenital malformations
Monitor eyes and renal function before and during pregnancy

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19
Q

Council on the effects of pregnancy on pre-existing diabetes:

A

Insulin resistance increases in pregnancy
So increases insulin requirement
Acceleration of retinopathy
Deterioration in renal function if preexisting nephropathy
Risk of maternal hypoglycaemia in early pregnancy

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20
Q

Explain the principles of managing pre existing diabetes in pregnancy:

A

Pre-conception counselling - improve control
Manage with diabetes team
Stop ACEi and Statins
Screen for and monitor vascular complications

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21
Q

Explain the Oral Glucose Tolerance Test:

A

Used to screen high risk women for gestational diabetes
Performed between 24-28 weeks
Fasting venous plasma glucose measured
Given a drink containing 75g of glucose
Venous plasma glucose measured again at 2 hours
Fasting: >5.6 or 2 hour: >7.8 mmol/L

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22
Q

Who gets screened for gestational diabetes?

A
BMI >30
Previous gestational diabetes
Previous big baby >4.5kg 
First degree relative with diabetes 
Ethnic groups - South Asia, Black, Arab 

Previous unexplained still birth
Polyhydramnios
Large for dates in this pregnancy
PCOS

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23
Q

Can a woman take an ACEi during pregnancy?

A

No - ACE inhibitors are contraindicated during the second and third trimesters of pregnancy because of increased risk of fetal renal damage.

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24
Q

Can a woman take a statin during pregnancy?

A

Women wishing to become pregnant should stop use of statins three months prior to attempting to conceive, or as soon as pregnancy is confirmed, due to the theoretical risk of fetal abnormality

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25
What is the stepwise management of gestational diabetes?
1. Conservative: - Refer to dietician - Exercise, walk for 30 mins after meals 2. Medical: Metformin 500mg daily with food - Can increase dose after a week 3. Single injection intermediate acting insulin 4. Add short acting insulin before meals
26
What is the obstetric management of pre existing and gestational diabetes?
Serial growth scans to predict macrosomnia Plan for induction at 38-40 weeks Be alert for possible shoulder dystocia If already >4.5kg consider elective c-section Close neonatal monitoring of blood sugars
27
What is the immediate management of shoulder dystocia
McRoberts manœuvre - flex and externally rotate the hips Suprapubic pressure Episiotomy - for access for advanced intervetions
28
What advanced interventions can be performed for shoulder dystocia when McRoberts and Suprapubic pressure fail?
Woodscrew manoeuvre - Rotate the shoulder - Deliver posterior arm - Break clavicle Zavanelli manoeuvre - Emergency c-section
29
Explain gestational hypertension
BP >140/90 on more than one occasion Onset after 20 weeks 15% risk of developing pre eclampsia
30
Explain Pre-eclampsia:
A disease of the placenta that starts after 20 weeks if the arteries fail to remodel themselves, making blood flow poor. It causes high blood pressure, protein in the urine and sometimes swelling of the hands, face and ankles. It resolves within an few days of delivery but can lead to some serious complications for the mother and the baby.
31
What is the treatment for hypertension in pregnancy and what is the target BP?
Labetalol - 1st line, to reduce stroke risk Nifedipine or Methyldopa - 2nd line Target range <150 systolic Over treatment can cause IUGR
32
What is used for the prevention of pre eclampsia in high risk patients?
Aspirin 75mg from 12 weeks
33
Who is at high risk of pre-eclamsia and should receive prophylactic aspirin 75mg from 12 weeks?
ECLAMP ``` Existing hypertension Chronic kidney disease Lupus (SLE) Antiphospholipid syndrome Maternal diabetes Previous pregnancy with hypertension ```
34
What are the maternal complications of pre-eclampsia?
SHAME ``` Stroke HELLP syndrome Abruption of placenta Multi organ failure +/- DIC +/- Death Eclampsia ```
35
What are the fatal complications of pre-eclampsia?
Foetal growth restriction Intra-uterine death Premature delivery - iatrogenic
36
What is HELLP syndrome?
Haemolysis Eleveated Liver enzymes Low Platelets
37
What are investigations should you perform when suspecting pre-eclampsia?
Bedside: - BP 2 readings, - Urine dip Once confirmed - do pre-eclampsia bloods FBC - low platelets U&E - raised urea and creatinine LFTs - raised AST Low Hb and high bilirubin if haemolysis = HELLP
38
What 4 red flag symptoms predict eclampsia?
Headache Visual disturbances Epigastric or RUQ pain - hepatic capsule distension Breathlessness - pulmonary oedema due to ARDS
39
What 3 red flag signs predict eclampsia?
Peri orbital oedema Hyper-reflexia Clonus
40
What is the emergency management of Eclampsia?
ABC Turn patient onto left side IV Magnesium sulphate IV labetalol
41
How would you investigate suspected pre labour rupture of membranes?
Sterile speculum - looking for pooling of amniotic fluid - Foetal fibronectin - Amnisure - Placental alpha-microglobulin-1 Urine dip for infection CTG Bloods: FBC, U+Es, CRP
42
Management of pre labour rupture of membranes:
Admit for observations Most will labour spontaneous within 24 hours Offer induction at 24 hours
43
Management of pre term labour:
Betamethasone 12mg IM x 2 doses, 24h apart Consider tocolytics Consider transfer to tertiary unit - Intrapartum antibiotics
44
Management of preterm prelabour rupture of membranes:
``` Admit for observation 80% chance of labour with 7 days Betamethasone 12mg IM x 2 doses, 24h apart Erythromycin 250mg QDS for 10 days Consider transfer to tertiary unit ```
45
What is the antenatal management twins?
``` Oral Iron, Folic acid 5mg, Aspirin 75 mg Detailed anatomy scan and cardiac scans Regular growth scans - DCDA 4 weekly (from 16 weeks) - MCDA 2 weekly (from 16 weeks) - MCMA Regular BP and urine checks ```
46
What is the obstetric management of twins?
Vaginal delivery if presenting twin cephalic If breech then c-section Aim to deliver at: DCDA = 37-38 weeks MCDA = 36 weeks MCMA = 32-34 weeks by C-section regardless
47
How is the donor twin affected in twin-twin transfusion syndrome of monochorionic twins?
Anaemic Growth restricted Oligohydramnios Hypotension
48
How is the recipient twin affected in twin-twin transfusion syndrome of monochorionic twins?
``` Polycythaemic Hypertensive Cardiac hypertrophy Oedema (hydrops) Polyhydraminios ```
49
What is defined as small for gestational age?
less that the 10th percentile for gestational age
50
What are the possible reasons a small for gestational age foetus?
SWAN Starved small - IUGR Wrong small - wrong dates Abnormal small - Chromosomal, Infection Normal smal - constitutional
51
Who is it high risk of IUGR?
SHIT Smoking Hypertension IUGR previously Twins
52
What will be seen on US of a foetus with IUGR?
Brain sparing effect of placental insufficiency Abdominal circumference affected more than head Increasing placental resistance - Absent end diastolic flow - Reversed end diastolic flow
53
Management of a foetus with absent or reversed end diastolic flow on US:
Intensive surveillance - CTG, USs Consider early delivery Steroids is < 34 weeks
54
Between what gestation ages are maternal steroids beneficial for a pre term neonate?
24 - 34 weeks
55
What defines an antepartum haemorrhage?
Bleeding in pregnancy after 24 weeks Bleeding before 24 weeks is a threatened miscarriage
56
What are the possible causes of an antepartum haemorrhage?
``` Uterine: - Placental abruption - Placenta praevia - Vasa praevia - Marginal bleed (from the placental edge) Cervical: - 'Show', loss of mucus plug - Cervical polyp or ectropion - Cervical cancer Vaginal: - Trauma or infection ```
57
Painless, bright red vaginal bleeding in a pregnant woman suggest what?
Placenta praevia
58
Painful, vaginal bleeding with dark red blood in a pregnant woman suggest what?
Placental abruption
59
How do you investigate cause of antepartum haemorrhage?
Do NOT do a vaginal exam until after placental site has been confirmed by ultrasound
60
What is the immediate management of antenatal haemorrhage:
Call for help from seniors ABC approach 15L non re-breath oxygen, Tilt bed head down and put in left lateral position 2 large bore cannulae & give 500mls 0.9% saline Send bloods for FBC, clotting screen, GXM 4 units blood Urinary catheter Check fetal condition - CTG If necessary give O negative Assess cause of bleeding - US
61
What is the immediate management of post partum haemorrhage:
Call for help - senior staff plus pairs of hands ABC approach 15L non re-breath oxygen & tilt bed head down 2 large bore cannulae & give 500mls 0.9% saline Send bloods for FBC, clotting screen, GXM 4 units blood Urinary catheter If necessary give O -ve blood +/- FFP and platelets Assess cause of bleeding
62
What defines a primary post partum haemorrhage?
loss of > 500ml of blood within 24 hour of delivery
63
What defines a secondary post partum haemorrhage?
excessive bleeding from the genital tract between 24 hours and 6 weeks post-partum
64
What are the primary causes for post partum haemorrhage?
4 Ts of PPH Tone - uterine atony Tissue - retained placenta, prolonged third stage Trauma - vaginal or cervical tear Thrombin - pre-eclampsia or DIC
65
What are the risk factors for uterine atony?
Previous episode of PPH Prolonged third stage Multiple pregnancy Fetal macrosomia Polyhydramnios
66
What is the initial pharmacological management of post partum haemorrhage?
Ergometrine IV bolus | Syntocinon infusion
67
What is the stepwise surgical treatment for post partum haemorrhage ?
``` Evacuation of retained placenta Intrauterine balloon tamponade Haemostatic suture Internal iliac ligation Consider hysterectomy ```
68
When should Anti-D be given and why?
Routinely as 28 and 34 weeks or at a sensitising event To prevent rhesus D alloimunisation in D negative women who may be carrying a D positive foetus
69
What are examples of a sensitising event that would require extra Anti-D?
``` Chorionic Villus Sampling Amniocentesis Termination of pregnancy Threatened or complete miscarriage after 12 weeks Antepartum haemorrhage External cephalic version Closed abdominal injury ```