9) Maternal Medicine - Renal

Question 1

Incidence of AKI

Answer 1

1.4% of obstetric admissions

Question 2

Fall in creatinine in pregnancy

Answer 2

35micromol/L (average creatinine 53)

Question 3

What should be considered diagnostic of kidney injury?

Answer 3

New creatinine >90

Question 4

Most common cause of AKI in pregnancy

Answer 4

Pre-eclampsia

Question 5

Indications for renal replacement therapy

Answer 5

• Metabolic acidosis
• Hyperkalemia
• Fluid overload refractory to medical treatment
• Pregnancy specific: Urea >17 mmol/L*

Question 6

What percentage of PET leads to AKI?

What percentage of HELLP leads to AKI?

Answer 6

PET: 1.5-2%
HELLP: 3-15%

Question 7

Pathology finding in kidney in PET + HELLP

Answer 7

Glomerular endotheliosis (reduces glomerular capillary permeability therefore reducing filtration).

In HELLP, additional thrombotic microangiopathy.

Question 8

How to adjust dose of MgSO4 in AKI?

Answer 8

If urine output <20ml/h or creatinine >90,

50% reduction in infusion rate of MgSO4 (still give bolus) and monitor Mg levels every 4-6h (aiming 2-3.5)

Question 9

Incidence of thrombotic microangiopathy (TTP/HUS)

Answer 9

1 in 25,000

Question 10

What is the pathology underlying TTP & HUS

Answer 10

TTP: ADAMTS13 (levels fall in pregnancy)
HUS: Abnormality in complement activation

Question 11

What percentage of TTP in pregnancy leads to AKI?

Answer 11

30-80%

Question 12

Incidence of ESRF in HUS

Answer 12

75%

Question 13

When does TTP occur and when does HUS occur?

Answer 13

TTP in 2nd/3rd trimester.

HUS postpartum.

Question 14

Factors distinguishing HELLP from TTP/HUS

Answer 14

• Profoundly low platelets more common TTP/HUS
• Liver function not usually affected TTP/HUS (except increased bilirubin)
• AKI more common TTP/HUS
• Coagulopathy more common HELLP (anti-thrombin and fibrinogen increased in TTP/HUS)

Question 15

Incidence of AFLP

Answer 15

5 per 100,000

Question 16

Incidence of AKI in AFLP (and percentage requiring renal replacement therapy)

Answer 16

14% develop AKI

3.5% require renal replacement

Question 17

What happens in AFLP?

Answer 17

Fetal homozygosity of disorders of beta-fatty acid oxidation leading to excessive fatty acid load in mother.

Question 18

Kidney biopsy in AFLP

Answer 18

Tubular free fatty acid deposition

Question 19

Things to distinguish AFLP from HELLP

Answer 19

• Low serum glucose
• Raised serum ammonia
• Prodromal vomiting

Question 20

What percentage of cases of SLE have renal involvement?

Answer 20

20-50%

Question 21

What USS finding would suggest pathological renal obstruction?

Answer 21

If ureter dilated distal to pelvic brim, if obstruction does not decompress by positioning on all fours and if ureteric jets absent in contralateral position.

Question 22

Most common cause of acute interstitial nephritis

Answer 22

NSAIDs

Question 23

What percentage of people using NSAIDs develop significant effects or acute renal failure?

Answer 23

1-5% side effects

0.5-1% acute renal failure

Question 24

Incidence of renal transplant

Answer 24

2-6 per 10,000 women of childbearing age

Question 25

Number of pregnancies in women with renal transplants

Answer 25

30-40 annually

Question 26

How long to wait after a renal transplant before conceiving?

Answer 26

1 year

Question 27

Risk of acute rejection of renal transplant in first year?

Answer 27

10-15%

Question 28

Effect of pregnancy on risk of renal graft rejection

Answer 28

If graft function normal then pregnancy doesn't increase risk of rejection

Question 29

What to switch mycophenolate to in transplant patients and when?

Answer 29

Switch to azathioprine and allow 3/12 washout period

Question 30

Hypertension in patients with renal transplant

Answer 30

- 50% have hypertension predating and persisting pregnancy | - 15% new onset in pregnancy

Question 31

GDM in patients with renal transplant

Answer 31

- 5-25% | - Calcineurin inhibitors are diabetogenic

Question 32

What pre pregnancy renal parameter predicts increased rate of loss of maternal renal function?

Answer 32

>1g/day

Question 33

What proportion of people with a renal transplant see their creatinine increase and by what amount?

Answer 33

38% see creatinine increase >20%

Question 34

Acute rejection rates for renal transplant during pregnancy

Answer 34

2-4%

Question 35

Effect of renal transplant on delivery?

Answer 35

Vaginal delivery recommended with continuous CTG | Caesarean rates increased

Question 36

Change in proteinuria in pregnancy in a patient with a transplant

Answer 36

Expect to double (and further double if ACEi/AR2 stopped)

Question 37

When do renal transplant patients require VTE prophylaxis?

Answer 37

If PCR>300 or ACR>180

Question 38

Effect of renal function on screening tools

Answer 38

Reduced urinary bhCG excretion therefore falsely elevated results.

Question 39

How often to monitor renal function and pre-dose tac/ciclosporin levels?

Answer 39

At least monthly

Question 40

Risk of injury to kidney at CS

Answer 40

1-2%

Question 41

Risk of PET in kidney donors

Answer 41

2 x increased risk (should have aspirin prophylaxis!)

Question 42

When does pancreatic transplant usually occur?

Answer 42

In conjunction with renal transplant.

Question 43

Rate of adverse outcomes with liver transplant

Answer 43

Less than renal

Question 44

Rejection rate with liver transplant

Answer 44

10%

Question 45

Rate of adverse outcomes with cardiothoracic transplant

Answer 45

Comparable to renal

Question 46

Overall incidence of urinary tract infection in pregnancy

Answer 46

8%

Question 47

Definition of asymptomatic bacteriuria

Answer 47

>10^5 bacteria in absence of symptoms

Question 48

Incidence of asymptomatic bacteriuria

Answer 48

2-10%

Question 49

What percentage of cases of asymptomatic bacteriuria progress to symptomatic urinary sepsis if untreated?

Answer 49

40% (30% cystitis, 50% pyelonephritis)

Question 50

Incidence of symptomatic cystitis

Answer 50

2%

Question 51

Incidence of pyelonephritis

Answer 51

2%

Question 52

What percentage of cases of pyelonephritis are associated with bacteraemia?

Answer 52

15-20%

Question 53

What is the recurrence rate of pyelonephritis?

Answer 53

20%

Question 54

Most common organism for UTI

Answer 54

E. Coli (second: S. saprophytic)

Question 55

Incidence of recurrent UTI in pregnancy

Answer 55

4-5%

Question 56

What treatment for renal stones is contraindicated in pregnancy?

Answer 56

Lithotripsy

Question 57

Three severities of CKD

Answer 57

Mild: Cr <125 Moderate: Cr 125-250 Severe: Cr >250

Question 58

Effect of pregnancy on renal function in mild CKD

Answer 58

2% loss of function | 0% permanent deterioration

Question 59

Effect of pregnancy on renal function in moderate CKD

Answer 59

40% loss of function 20% permanent deterioration 2% ESRF

Question 60

Effect of pregnancy on renal function in severe CKD

Answer 60

70% loss of function 50% permanent deterioration 35% ESRF

Question 61

Pre-eclampsia in CKD

Answer 61

20% Mild CKD 40% Moderate CKD 60% Severe CKD 75% Dialysis

Question 62

FGR in CKD

Answer 62

25% Mild CKD 40% Moderate CKD 65% Severe CKD >90% Dialysis

Question 63

PTB in CKD

Answer 63

30% Mild CKD 60% Moderate CKD 90% Severe CKD >90% Dialysis

Question 64

Perinatal mortality with CKD

Answer 64

1% Mild CKD 5% Moderate CKD 10% Severe CKD 50% Dialysis