Renal disease Flashcards
renal physiology in pregnancy
Renal blood flow and GFR increase by 80%
- -> increased urinary frequency
- -> increased CrCl and lower serum Cr
- -> increased protein and glucose in urine
Renal hydronephrosis (R>L, up to 15-20mm on right) - progesterone = smooth muscle relaxation, compression from gravid uterus
Urinary stasis –> predisposed to UTI
Asymptomatic bacteriuria
Occurs in 2-5% of pregnant women
A/w pyelo (30%), PTL
UTI treatment 3-7 days
Recurrent UTI x3 confirmed with MSU (or pyelo) then prophylaxis and consider renal USS
Pyelonephritis
2% of pregnancies
E. coli - leading cause (other Klebsiella, Proteus and Enterobacter organisms)
Risks:
- PTB
- Recurrence (20%)
Rx: analgesia, IVF cefuroxime Avoid gent (fetal ototoxicity) VTE prophylaxis IDC and fluid balance (if septic) Prophylaxis, monthly MSU
Renal stones diagnosis and management
No increased risk of forming stones in pregnancy
USS - will identify 50%
Consider MRI
Conservative
- Successful in 70%
- IVF, analgesia, antibiotics
Nephrostomy if evidence of obstruction on imaging
Long-term management - insertion of JJ stents
Lithotripsy contraindicated in pregnancy
CKD pre-pregnancy counselling
MDT approach Optimise BP and diabetes - Poor control a/w worse prognosis Baseline urea, creatinine and PCR FBC - Assess for anaemia of chronic disease - Booking bloods and serology as immunocompromised (CMV, TORCH) Stabilise disease on low doses of medication Folic acid 5mg Lifestyle advice Consider genetic counselling for inherited conditions Aspirin and calcium when pregnant Progesterone pregnancy
Common renal meds safe in pregnancy
Tacrolimus
- Check levels each trimester
Cyclosporin
- Check levels each trimester
- Increased risk of GDM
Prednisone
- Increased risk of GDM
- Fetus exposed to 10% of maternal dose
- IV hydrocortisone in labour
Azathioprine
- Increased risk of IUGR and PTL
Labetalol
Nifedipine
Clexane
Renal meds contraindicated in pregnancy
Mycophenolate - Increased risk of miscarriage and congenital defects, Switch >3/12 pre-pregnancy to azathioprine
Methotrexate
Cyclophosphamide (teratogenic)
Rituximib (neonatal B cell depletion)
ACE-inhibitors - Fetal renal failure, oligohydramnios, pulmonary hypoplasia
Risk of pregnancy on renal function
Creatinine <125
- Good outcomes
- 2% will have worsening function, does not persist PP
Creatinine 125-180
- 40% worsening function
- 20% persist PP
- 2% progress to ESRF
Creatinine >180
- 50% worsening renal function PP
- 35% progress to ESRF
Risks of renal disease on pregnancy
PET, IUGR
- 25% with mild (Cr <125)
- 60% with Cr >180
PTB
- 30% with mild
- 90% with severe (Cr >180)
C-section (3x increased)
Anaemia
Vitamin D deficiency
Implications of dialysis on pregnancy
50% perinatal mortality rate
Fertility reduced
Chance of successful pregnancy <50%
High urea = risk of polyhydramnios and fetal death
- Increase dialysis duration to control urea, aim for <15
Implications of renal transplant on pregnancy
> 2y after transplant for conception
Should be stable on medications for 1-2y prior to conception
Successful pregnancy outcomes for 95% who reach second trimester
Prognosis related to graft function at conception
No adverse effects on graft survival if Cr <100
- Cr >130 - 65% graft survival at 3y
Chance of graft rejection during pregnancy = 2%
Vaginal birth preferred mode of delivery
- Higher rates of CS than general population
- If CS then risk of 1-2% injury to transplanted kidney or ureter
Immunocompromised, therefore IV antibiotics for any surgical procedure (including episiotomy)
Antenatal management of CKD
MDT Meds: - Supplement folic acid and vitamin D - Low dose aspirin and calcium Bloods baseline: - FBC for anaemia - PET screen VTE risk assessment - Nephrotic range proteinuria --> clexane Control BP Monitor for PET regularly - Difficult to distinguish between PET and worsening renal function, therefore consider placental growth factor blood test Monitor renal function (with Cr not eGFR) Serial growth scans
What is a phaeochromocytoma
Catecholamine-secreting tumours Adrenal medulla (90%) Along the sympathetic chain (paragangliomas)
Clinical features
- Palpitations, sweating, anxiety
- Glucose intolerance
- Headache
- Labile HTN
Sudden attacks
Diagnosis of phaeochromocytoma
Elevated urine (24h collection) or plasma catecholamine Localisation of the tumour - USS and MRI
Effect of phaeochromocytoma on pregnancy
High risk of hypertensive crisis and maternal death (up to 15%)
- Can be precipitated by labour, vaginal or CS delivery, opiates
High fetal mortality (30%)
Main causes of death - cardiac arrhythmia, cerebrovascular disease, pulmonary oedema
Management of phaeochromocytoma
Alpha-blockade, e.g. phenoxybenzamine, to control HTN
Once adequately alpha blocked, introduce beta blocker to control tachycardia
Serial USS (because risk of FGR with beta blocker)
Planned CS recommended
- Increased risk of maternal deaths during labour
Surgery before 24/40 for tumour removal
- After 24/40 delay until fetal maturity
- Or delay until PP
- Need 3 days of adequate beta blockage before OT
What is conn’s syndrome? and how does it present
Primary hyperaldosteronism secondary to adrenal adenoma, hyperplasia or malignancy
HTN
Hypokalaemia
Metabolic acidosis
Aldosterone - essential for sodium conservation
Diagnosis of Conn’s syndrome
Difficult in pregnancy as aldosterone levels naturally increase
Traditional diagnostic test: raised aldosterone : renin ratio
Adrenal USS or MRI
Management of Conn’s syndrome
Case reports suggest defer surgery until PN - Unless malignancy suspected Medical management - Antihypertensives - Potassium supplements - Potassium-sparing diuretics
Avoid:
- Spironolactone - Under-virilisation of male fetus
Implications of polycystic kidney disease on pregnancy
Risks in pregnancy:
- PET
- UTIs
Bleeding into renal cyst –> loin pain, haematuria
Pregnancy has no adverse long-term effect on renal function
May be associated with:
- Polycystic liver disease - May enlarge during pregnancy
- Subarachnoid haemorrhage from intracranial aneurysms
