Chronic Kidney Disease in Pregnancy

Find out your stage, because it drives everything

NICE guideline NG121 organises intrapartum care for kidney disease almost entirely around CKD stage, and the recommendations differ sharply between them. Knowing whether you are considered stage 1, 2, 3a, 3b, 4 or 5 answers most of your questions about what your pregnancy will look like.

NICE guideline NG203 sets out how that staging is done outside pregnancy, using eGFR together with an albumin:creatinine ratio. NG203 recommendation 1.1.13 regards "a confirmed ACR of 3 mg/mmol or more as clinically important proteinuria", and recommendation 1.1.12 says a repeat sample is not needed if the initial ACR is 70 mg/mmol or more.

Why your eGFR stops being reliable

This catches people out because the number they have watched for years suddenly cannot be trusted. NG203 states explicitly that eGFR based on creatinine "may be less reliable in certain situations", and names pregnancy among them, alongside acute kidney injury and oedematous states.

The physiological reason is that kidney blood flow and filtration rise substantially in normal pregnancy, so serum creatinine falls and an eGFR calculated from it overestimates function. A creatinine that would be reassuring outside pregnancy can be abnormal within it. This is why kidney function in pregnancy is followed using serial creatinine and protein measurements interpreted against your own baseline, rather than a single eGFR figure.

Get a baseline early. Without a first-trimester creatinine and urine protein measurement there is nothing to compare a third-trimester result against, and that comparison is the whole game.

Birth timing, by stage, with the exact NICE wording

NICE NG121 recommendation 1.8.12: for women with CKD stage 1, stable renal function and non-nephrotic-range proteinuria, defined there as a urine protein:creatinine ratio less than 300 mg/mmol, "base decisions on timing and mode of birth on the woman's preference and obstetric indications". In other words, mild stable kidney disease does not by itself change your birth plan.

Recommendation 1.8.13: consider planned birth by 40 weeks plus 0 days for women with CKD stage 1 and nephrotic-range proteinuria (urine protein:creatinine ratio greater than 300 mg/mmol), or CKD stage 2 to 4 with stable renal function.

Recommendation 1.8.14: for CKD stage 5, or deteriorating stage 3b and stage 4, before 34 weeks, discuss the option of dialysis with the multidisciplinary team "in an effort to prolong the pregnancy to at least 34+0 weeks".

Recommendation 1.8.15: for the same group after 34 weeks, discuss planned birth and "consider birth no later than 38+0 weeks".

Recommendation 1.8.16: for all women with kidney disease, including those with a kidney transplant, base mode of birth on preference and obstetric indications. Kidney disease is not in itself a reason for a caesarean.

Note the units. NICE uses protein:creatinine ratio in mg/mmol here, while NG203 uses albumin:creatinine ratio for staging outside pregnancy. They are different measurements and the numbers are not interchangeable.

Who should be in the room

NG121 recommendation 1.8.1 asks that a clinician with expertise in managing renal conditions in pregnant women be involved in risk assessment during pregnancy. Recommendation 1.8.2 goes further for CKD stage 4 or 5 before pregnancy, or progressive or active disease: intrapartum care by a midwife, obstetrician and obstetric anaesthetist, with input from that renal clinician, who recommendation 1.8.3 says should be available for consultation during the intrapartum period.

Recommendations 1.8.10 and 1.8.11 ask for the intrapartum plan to be made "as early as possible during pregnancy" where kidney disease is due to lupus nephritis, vasculitis or glomerulonephritis, and, for kidney transplant recipients, with a transplant surgeon involved as well.

Fluid balance monitoring in labour

Recommendation 1.8.5 sets out what happens during labour: hourly heart rate, and at least every 4 hours blood pressure, respiratory rate with chest auscultation, fluid input and output, and oxygen saturation, with an individualised plan after each assessment aimed at maintaining normal fluid volume to reduce the risks of acute kidney injury and pulmonary oedema.

Recommendation 1.8.6 asks for renal function to be assessed at least every 24 hours during the intrapartum period, "because prolonged labour may lead to dehydration and acute kidney injury". Recommendation 1.8.8 prohibits nephrotoxic drugs including non-steroidal anti-inflammatories in the intrapartum period for women with kidney disease. That last point is worth having in your notes, because NSAIDs are otherwise routine pain relief after birth.

Recommendation 1.8.9 continues the same four-hourly monitoring for at least 24 hours after birth and asks for postpartum assessment of renal function and follow-up for persistent kidney disease.

Pre-eclampsia: the hardest overlap

Rising blood pressure and increasing proteinuria are features of both worsening CKD and pre-eclampsia, and the treatments differ. NICE guideline NG133 covers diagnosis and management of hypertension in pregnancy, including the assessment of proteinuria and the features indicating severe disease. NG121 recommendation 1.8.4 simply says to manage acute kidney injury secondary to pre-eclampsia in line with that guideline.

The practical consequence is that women with CKD are usually assessed for pre-eclampsia risk early and offered aspirin where risk factors are present; it is named here without a dose because it is a prescribed medicine. Blood pressure and urine are checked more often than in routine care, which NICE guideline NG201 sets out for everyone else.

Medicines and transplants

Several drugs commonly used in kidney disease, particularly ACE inhibitors and angiotensin receptor blockers, are changed before or as soon as pregnancy is confirmed. Immunosuppressants after transplant are generally continued, with some agents swapped in advance. All of these are named without doses here, because the substitutions are individual and specialist.

The NHS pages on chronic kidney disease describe the underlying condition and its usual monitoring, and the NHS lupus pages are relevant if your kidney disease is due to lupus nephritis, which NG121 singles out for early intrapartum planning.