Renal Disease In Preg

Renal disease in pregnancy

Dr Omoregie

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synopsis Introduction. Renal system changes in normal pregnancy. Pregnancy in women with pre-existing renal disease. Specific renal diseases in pregnancy. Counselling patient with chronic renal disease. Management guidelines Delivery Pregnancy in dialysis patients Pregnancy in renal transplant recipients Conclusions. Dr Omoregie

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introduction The attitude of clinicians towards pregnancy in women with CRD has changed tremendously in the last 3 decades. Previously the advise was therapeutic abortion followed by sterilisation – this pessimism was succinctly stated in a Lancet editorial of 1975 which stated that…’Children of women with renal dz used to be born dangerously or not at all – not at all if their doctors had their way.” The current practice, based on clinical evidence is one of cautious optimism. Most pregnancies succeeds provided renal impairment and/or hypertension are minimal. Dr Omoregie

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Renal system changes in preg GFR and renal plasma flow increases by 5070% above the non-pregnant value. 24-hr creatinine clearance increases immediately after conception. Plasma levels of creatinine and urea which average 73µmol/l and 4.3mmol/l in the nonpregnant state decrease to mean values of 51µmol/l and 3.1mmol/l in pregnancy. The kidneys enlarges in pregnancy – its length on x-ray increasing by approximately 1cm. Dr Omoregie

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The calyces, renal pelves and ureter dilate markedly – all these occurring very early in pregnancy. Clinical implications It should not be mistaken for obstructive uropathy. Stasis of urine within the ureters may increase the incidence of acute pyelonephritis in pregnant women with asymptomatic bacteriuria. There may be errors in test based on timed urine collections. Post-partum x-ray examination of the urinary tract should be delayed until at least 12-16wks after delivery to allow the changes to resolve. Dr Omoregie

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Urinary protein levels are slightly higher in pregnancy – may be due to changes in the tubular function. A normal urine in the non-pregnant may contain up to 200mg/l of protein; whereas up to 300mg/l is considered normal in preg and occasionally it may be up to 500mg/l without significant renal disease. The dipstick testing of urine often shows trace of protein during pregnancy: the sensitivity of the kit is set for the nonpregnant state. Dr Omoregie

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Preg in women with pre-existing renal disease The frequency of acute pyelonephritis increases. Pregnancy has no adverse effect on the natural history of established renal parenchymal disease, provided the renal function is minimally compromised and hypertension is absent – mild to moderate renal dysfxn (e.g. plasma creatinine <125µmol/l, creatinine clearance >60ml/h) usually have successful pregnancy with normal fetal outcome. Dr Omoregie

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Specific renal diseases in preg Acute glomerulonephritis complicating preg is rare – when it occurs it is mistaken for preeclampsia. Chronic glomerulonephritis – the course of preg should not be complicated, if the patient is normotensive. Unfortunately hypertension often supervenes early in the course of such a pregnancy. UTI may occur more frequently. Lupus nephropathy – due to SLE, view is controversial. Prognosis most favourable if dz was in remission >6 months prior to conception, steroid dosage should be increases postpartum. Dr Omoregie

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Renal disease due to scleroderma and periarteritis nodosa results in dismal preg outcome with many cases ending in maternal death. Diabetic nephropathy – pregnancy has no adverse effect on renal lesion, but the frequency of UTI, oedema and/or pre-eclampsia is increased. Urolithiasis during pregnancy has a prevalence of 0.03-0.35%, most of the renal stones contain calcium. The course of the disease is not affected by pregnancy. Note – it is a major cause of non-obstetrically related abdominal pain during pregnancy. UTI can be more frequent. Dr Omoregie

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Polycystic kidney dz – preg well tolerated, provided renal function is preserved and hypertension is absent. Pregnancy is well tolerated by women with single and normally situated kidney. Pelvic kidneys – pregnancy is well tolerated, dystocia rarely occurs with a pelvic kidney. Decreased fetal salvage is due to other malformations of the urogenital tract.

Dr Omoregie

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Counselling patient with CRD Is pregnancy possible? Will pregnancy be complicated? Will the pregnancy result in a healthy baby? Will the pregnancy cause any long-term harm? Pregnancy in women with CRD is possible depending on the degree of renal impairment and the absence of hypertension, rather than the underlying parenchymal renal lesion. Dr Omoregie

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Therefore, pregnancy is restricted to those whose plasma creatinine levels are 250µmol/l or less and who have a DBP of 90mmHg or lower (preferably below 80mmHg) The prospective mother should be counselled on the need for close monitoring during pregnancy, the increased risk of hypertension complicating the pregnancy and the likelihood of terminating the pregnancy as a result of this complication. Women with proteinuric disease should be advised that oedema will most likely appear – or if present worsen: but that these signs are mainly cosmetic and usually do not jeopardise the pregnancy. Dr Omoregie

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The chances of producing a healthy child is good for those with minimal renal dysfunction.

Dr Omoregie

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Guidelines for management Pre-conception care – planned pregnancy - Good diet, no smoking, no alcohol Uncomplicated antenatal course - ANC visit - 2 weekly until 32 wk gestation and thereafter weekly until delivery - Assessment in the ANC - Booking clinic – Hx, physical exam – wt, Ht, BP, FH, lie, presentation, FHR - Investigations – PCV, blood group, genotype, VDRL, urinalysis&m/c/s, ? USS etc. - Drugs - Malarial chemoprophylaxis + haematinics Dr Omoregie

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Subsequent visits – Hx, P.E, wt, FH, lie, presentation, FHR, urinalysis, PCV. Supplementary investigations Assessment of renal function: 24hr creatinine clearance and 24hr protein excretion. Urine m/c/s (early detection of asympt bacteriuria). Early detection of pre-eclampsia Assessment of fetal size, development & well being. Dr Omoregie

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Further Mx If renal fxn deteriorates – seek for cause If reversible (UTI, dehydration or electrolyte imbalance) treat and allow pregnancy to continue. When proteinuria occurs and persist, but BP is normal and renal function is preserved, the pregnancy should be allowed to continue. BP – moderate hyptension (DBP<110mmHg) need not be treated, treatment of severe Ht (DBP>110mmHg) is necessary for maternal well being and also allows the preg to continue, so has to achieve a further fetal maturation prior to delivery. Dr Omoregie

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Fetal surveillance – necessary since IUGR is associated with renal dz in pregnancy. USS, antenatal cardiotocography, fetal pulm maturity (L/S ratio). Delivery - Induce labour at 38wk – to prevent IUFD due to placental failure. Reasons for early delivery prior to 38wks - Evident renal fxn deterioration - Signs of imminent IUFD - Uncontrollable hypertension - Eclampsia Note: Delivery should only occur in centres with good fetal monitoring devices, operative delivery and neonatal resuscitation services 17 Dr Omoregie

Diagnosis of renal dz during pregnancy Occasionally noted for the 1st time during preg It is essential to try and establish a diagnosis If a patient presents with HT, proteinuria and/or abnormal renal fxn, it is difficult to distinguish renal parenchymal dz from pre-eclampsia. A previous hx of renal dz, abnormal urinalysis, a family hx of renal disorder or a hx of systemic illness known to involve the kidneys is very helpful. Note – renal parenchymal dz may coexist with preeclampsia. A definitive diagnosis usually defered until further assessment after delivery. Dr Omoregie

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Pregnancy in dialysis patients Patient usually have irregular or absent menstruation, decreased libido and impaired fertility – but they can conceive!! Therefore use contraception (if pregnancy is undesired). The outcome of preg is usually very poor Maternal condition may be compromised

Dr Omoregie

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Pregnancy in renal transplant recipient 40% of conception end up in spontaneous abortion, termination of pregnancy or ectopic gestation. 90% of the pregnancy that proceed beyond 1st trimester results in successful outcome. Criteria for successful outcome Good general health for 2yrs after transplant Stature compatible with good obstetric outcome. No proteinuria No significant hypertension No evidence of graft rejection No evidence of pelvicalyceal distension on a recent excretory urogram Stable GFR: plasma creatinine <180µmol/l Drug therapy: prednisolone<15mg/day and azathioprine <2mg/kg/day Dr Omoregie

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conclusion During normal pregnancy the urinary system undergo major morphologic and functional changes as exemplified by substantial and sustained renal haemodynamics which also occurs in women with pre-existing renal dz. With the exception of few, pregnancy has no adverse effect on the underlying renal dz, if the renal fxn prior to pregnancy is preserved and hypertension is absent. Although the fetal prognosis is less favourable than in healthy women, it does not justify discouraging pregnancy in women with renal disease. Dr Omoregie

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Women on haemodialysis should be on contraception, since there is reduced likelihood of a successful fetal outcome and there are many argument against pregnancy in these women. Pregnancy in women with renal transplant, once quite rare, has increased markedly in the recent past and the key to success is adequate pre-pregnancy assessment and meticulous antenatal care with cooperation between all the relevant specialities involved in her care. Dr Omoregie

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