renal conditions in pregnancy Flashcards
Renal physiological changes in pregnancy
Increased renal perfusion due to increased cardiac output perfusion increased 60-80% in T2, T3 50% increase (slight fall)
eGFR doesnt apply in pregnancy
Increased filtration - 55%
Drop in Cr / urea / bicarb measurement
Protein excretion is increased
PCR 30 mg/mmol or 300 mg / 24 hours
Microscopic haematuria is not uncommon in absence of infection and proteinuria
If USS normal no further Ix needed (unless persists post partum)
Physiological water and salt retention
Renal secretion of Vit D, renin and erythropoietin is increased
Physiological dilatation of the ureters and the caliceal collecting system in pregnancy R>L
this may be progesterone causing smooth muscle dilatation or obstruction from a gravid uterus
Normal pelvicaliceal diameter of 2 cm
Asymptomatic bacteriuria Incidence Significance - risk of progression What is the bug What is the cut off for bacterial load When does the infection occur
Affects 4-7% of pregnancies
40% develop acute cystitis
30% develop pyelonephritis
75-90% EColi - likely from large bowel (maybe ascending colonisation from sexual intercourse)
> 100,000 /mL
Non significant/ mixed growth should be repeated
Usually early in pregnancy
Treatment for asymptomatic bacteriuria
Must be treated reducing the risk of preterm babies and low birth weight
High risk of ascending infection
ABs depend on sensitivities
Tx for 3 days
Regular cultures to prove eradication
15% will require another course of ABs
What ABs do you avoid in which trimesters for UTI
Trimethoprim should be avoided in T1 due to anti folic action
Nitrofuritoin should be avoided in T3 as may precipitate neonatal haemolytic anaemia
Long acting sulphonamides should be avoided at the end of pregnancy due to the risk of neonatal kernicterus
Rate of acute cystitis in pregnancy
risk factors
How long to treat
1% of pregnancies
Risk factors: Diabetes Systemic steroid Immunosuppression Previous recurrent UTIs
again most are EColi
Treat 5-7 days
How to reduce the risk of recurrent UTIs in pregnancy
Pass urine after sexual intercourse
Perineal hygiene - wipe front to back
Double voiding to prevent residual in the bladder
Increase fluid intake - high volume dilute urine better
Incidence of acute pyelonephritis
Risk factors
Risk to pregnancy
Management
1-2%
Same as UTI (diabetes, immunosuppressed, on steroids, recurrent UTIs) as well as congential abnormalities of the renal tract, neuropathic bladder, calculi in the urinary tract, polycystic kidneys
Risk is of PTB
Management
Admission, IVAB for 24 hours then 2 weeks of orals
Monitor renal function for AKI
USS to exclude hydronephrosis, calculi or congential abnormalities
Antibiotic prophylaxis in pregnancy against infection of the urinary tract
if woman usually take prophylaxis - then keep taking it
Low dose cephalosporin / nitrofurantoin depending on sensitivities
(check resistance if intervening infection)
Once 2 or more UTIs in pregnancy - she should have a renal USS and prophylaxis should be considered
Local protocol 3 or more UTI or 1 pyelonephritis and monthly MSUs + prophylaxis
Chronic kidney disease
How does pregnancy affect CKD
Accelerated decline Escalating HTN Worsen proteinuria (this is exacerbated by withdrawal of ACEi) Flare of disease (especially if lupus)
What are the risks of pregnancy with CKD?
Miscarriage PTB HTN, PET IUGR Fetal death
The worse the renal disease the higher the risk
CKD 3-5 60-90% preterm
accelerated risk of renal decline 20-50%
What factors about renal disease affect outcome (of the CKD and the pregnancy)
Severity of renal disease
Renal disease is categorised by eGFR Stage 1-5
Woman with severe disease will have a decline and permanent worsening of their renal function
Woman with stage 5 disease are typically advised against pregnancy
HTN
Degree proteinuria
Underlying disease
Pregnancy dialysis patient
what is risks of pregnancy outcomes
50% perinatal mortality
90% PTB and IUGR
75% risk PET
What risks are associated with a high maternal urea?
Polyhydramnios (and associated Cord prolapse, PPROM and PTB) resulting from fetal polyuria due to the high osmotic load
Urea over 20-25 there is a risk of fetal death
Glomerulonephritis
Which types are worse?
What are the associated risk factors?
What are the pregnancy risks?
The type is less important then the compromise on renal function
If HTN - increased PET risk
Fetal loss and PTB 20%
3% overall decline in function from pregnancy
25% increase in BP - most reversible
Reflux nephropathy
How common is it?
What is the pregnancy risk?
What are the risk factors for deterioration?
How is it inherited?
1% of newborns
Most common renal disease in woman of childbearing age
25% risk PET - worse of bilateral scarring, HTN, Cr over 110
If no HTN/ normal Cr - risk PET 15% and HTN 30%
If renal disease present - can rapidly worsen
Particular association with IUGR
As autosomal dominant - child should be screened with a micturating cystogram
