Hypertension and associated complications in pregnant women with chronic kidney disease

Table 1 Chronic kidney disease patients who should avoid pregnancy

Chronic kidney disease patients who should avoid pregnancy	Ref.
Atypical hemolytic uremic syndrome if eculizumab is not available	Wiles et al[21]
Patient with active systemic lupus erythematosus or vasculitis	Puri et al[23]

Table 2 Renal replacement therapy for pregnant chronic kidney disease patients

Renal replacement therapy
Initiation of dialysis	Blood urea of more than 17 mmoL/L even in the absence of any frank uremic symptoms or absolute indication of dialysis, to prevent foetal death due to azotemia
Haemodialysis vs peritoneal dialysis	Lesser data on successful pregnancy outcomes in peritoneal dialysis patients
	Increased abortion rate during insertion of Tenckhoff peritoneal dialysis catheter
	Challenges to keep the usual dwell volume during peritoneal dialysis. Due to lesser space in the third trimester because of gravid uterus dwell volume needs reductions with concomitant increase in the number of exchanges to achieve the desired clearance
	Peritoneal dialysis: More frequent exchanges to maintain desired BUN
	Tidal peritoneal dialysis helps in reducing drain pain and catheter drain dysfunction due to the gravid uterus
Dialysis adequacy	Target predialysis BUN < 12.5 mmoL/L in hemodialysis. No recommendation established for peritoneal dialysis
	Dialysis duration
	Patients with residual renal function > 20 hours/week
	Patients without residual renal function > 36 hours/week
	Kt/V assessment should not be used in pregnancy
Weekly dry weight assessment to account for weight gain during pregnancy	2nd trimester: 300 g/week weight gain
	3rd trimester: 300-500 g/week weight gain
Segmental bioimpedance for accurate assessment of volume status	It might prevent intradialytic hypotension and subclinical reduction in effective arterial blood volume, which might avert worsening of uteroplacental perfusion and improve foetal outcome
Haemodialysis prescription	Bicarbonate around 25 mmoL/L
	Potassium 3 mmoL/L or more
	Heparin is generally safe in pregnancy

BUN: Blood urea nitrogen.

Table 3 Summary of recommendations for prevention and management of hypertension in pregnant chronic kidney disease patients

Multidisciplinary treating team involving consultant obstetrician, nephrologist and an expert midwifery team
Prevention strategies	Low dose aspirin to be started before 16 weeks pregnancy with dose > 80 mg/ day
	First trimester screening for pre-eclampsia for all chronic kidney disease patients
	Low-molecular-weight heparin prophylaxis in patients with previous adverse placenta-mediated obstetric outcomes
	Oral elemental calcium 1.5-2 g/day
	Dialysis requiring patients: Frequency of dialysis 5-7 times/week, duration > 20 hours/week, anuric dialysis patients should get high intensity dialysis > 36 hours/week
Management of hypertensive disorders	Regular blood pressure charting at every antenatal visit. Maintain blood pressure target < 135 mmHg/85 mmHg
	Magnesium sulphate can be given for prevention of eclampsia. Magnesium levels should be checked every 6 hours, and maintained less than 3.7 mmoL/L
	Maintain haemoglobin levels of 10-11 g/dL
	Recommended protein intake in dialysis patients is 1.8 g/prepregnancy weight/day + 20 g/day. Calorie requirement is 23–35 kcal/pregnant weight/day
	Immunosuppression levels to be regularly monitored and to ensure adequate immunosuppression
	Careful fluid management throughout pregnancy
	Neuraxial anaesthesia is preferred
	To avoid NSAIDs and nephrotoxic drugs

Table 4 How pregnancy and chronic kidney disease influence each other’s outcomes

Effect of CKD on pregnancy	Effect of pregnancy on CKD
Increased risk of pre-eclampsia	Loss of renal function
Prematurity	Higher risk of renal replacement therapy requirement in 1 year
Low birth weight
Foetal growth restriction
Polyhydramnios
Still-birth
Increased cesarean section rates (in diabetic nephropathy)
Maternal mortality (higher risk in diabetic nephropathy)

CKD: Chronic kidney disease.