Pregnancy Tutorial

Question 1

What is the purpose of an early pregnancy scan?

Answer 1

Viable pregnancy
Multiple pregnancies
Intrauterine
Gestational age; CRL (if over 12 weeks; use head circumference)
Placental position
Any obvious anomalies (anencephaly, gastroschisis, limb defects, major heart anomalies)

Question 2

What is the gestation of 6.64cm CRL?

Answer 2

12 + 2 weeks

Question 3

How is the robustness of a screening test assessed?

Answer 3

Specificity (true positive / (true + false neg)

Sensitivity (true neg / (true + false pos)

Question 4

What are the constituent components involved in 1st trim screening for down syndrome?

Answer 4

bhCG + PAPP-A
NT
Maternal age (>40)

Question 5

What is nuchal translucency?

Answer 5

Measure of thickness behind frontal neck - fluid

Question 6

From what gestation is NT valid?

Answer 6

11- 13 + 6 weeks

1st trim

Question 7

What is considered a normal NT?

Answer 7

<3.5mm

Question 8

Reasons for increased NT?

Answer 8

Chromosomal abnormalities; T 18, 21
Cardiac abnormalities
Turner’s syndrome

Question 9

What is MSAFP?

Answer 9

Maternal serum AFP -

Question 10

In what conditions is an increased MSAFP seen?

Answer 10

Multiple pregnancies
Placental abruption 
Anencephaly 
Spina bifida 
Gastroschisis

Question 11

What is pre-eclampsia?

Answer 11

Pregnancy-induced hypertension (>20 wks) in association with proteinuria (>0.3 g in 24 hours) with or without oedema

Question 12

What is the pathogenesis of pre-eclampsia?

Answer 12

Suboptimal uteroplacental perfusion associated with a maternal inflammatory response and maternal vascular endothelial dysfunction. This in turn leads to vascular hyperpermeability, thrombophilia and hypertension, which may compensate for the reduced flow in the uterine arteries

Question 13

What are the parameters for hypertension in pregnancy?

Answer 13

Systolic BP >140 mm Hg or diastolic BP >90 mm Hg

Question 14

What is HELLP syndrome?

Answer 14

Haemolysis
Elevated liver enzymes
Low Platelets

Question 15

Mode of action of labetalol?

Answer 15

Alpha and beta blocker

Question 16

Mode of action of betamethasone in neonate?

Answer 16

Increase lung maturity (surfactant production)
Decreased NEC
Decreased intraventricular haemorrhage

Question 17

Mode of action of hydralazine?

Answer 17

Peripheral vasodilatory via direction relaxation of vascular smooth muscle

Question 18

Mode of action of magnesium sulfate?

Answer 18

Peripheral and cerebral vasodilator
Anticonvulsant
Membrane stabiliser

Question 19

What is meant by rhesus neg?

Answer 19

No D antigens on the RBC of mother

Question 20

What is the mode of action of anti-D?

Answer 20

Neutralises foetal antigens in maternal blood to prevent mother isoimmunization resulting in the production anti-D antibodies which can have catastrophic effects on future pregnancies and on neonate

Question 21

What is seen in the blood of a sensitized mother?

Answer 21

Positive antibodies to D antigen

Question 22

In an affected rhesus positive baby, what would happen to the following cord blood parameters:
Hb
Bilirubin
Coombs test

Answer 22

Hb; decreased
Bilirubin; increased
Coombs test; positive (detects Abs that act against the surface of RBC)

Question 23

When should anti-D be given to prevent rhesus isoimmunisation following a sensitizing event?

Answer 23

Ideally within 72 hours

But up to 10 days

Question 24

What route is anti-D given?

Answer 24

IM

Question 25

How does the dose of anti-D differ based on gestational age?

Answer 25

<20 wks; 250 IU | >20 wks; 500 IU

Question 26

List some sensitizing events that warrant anti-D?

Answer 26

``` Post-partum; within 24 hours of a birth of Rh +ve baby Miscarriage >12 weeks ToP at any gestation Amniocentesis Trauma to abdomen ```

Question 27

When is routine prophylaxis given to Rh -ve women?

Answer 27

28 weeks; dose of 500 IU IM

Question 28

``` Would you administer anti-D in this case: Rh -ve mother ABO compatible Rh +ve baby Coombs test -ve Infant bilirubin level normal ```

Answer 28

Yes; give postpartum to prevent isoimmunisation

Question 29

``` Would you administer anti-D in this case: Rh -ve mother ABO incompatible Rh -ve baby Coombs test -ve Infant bilirubin level normal ```

Answer 29

No

Question 30

``` Would you administer anti-D in this case: Rh -ve mother ABO compatible Rh + baby Coombs test +ve Infant bilirubin level increased ```

Answer 30

Yes and no Mother already sensitized so anti-d antibodies already formed Need to monitor future pregnancies very carefully to assess foetus for anaemia and hydrops

Question 31

``` Would you administer anti-D in this case: Rh +ve mother ABO incompatible Rh -ve baby Coombs test +ve Infant bilirubin level increased ```

Answer 31

No; infant increased bilirubin due to ABO incompatibility not rhesus Monitor baby; keep hydrated Can offer phototherapy for jaundice

Question 32

What are routine components of antenatal care routine?

Answer 32

``` Weeks pregnant Height of uterus/ fundal height BP Urinalysis Oedema Fifths palpase Foetal lie and presentation FHR Foetal movements FBC ```

Question 33

What changes occur normally in the maternal CV system?

Answer 33

Increased CO Increased HR Decreased BP in 2nd trim