What is the management approach for a pregnant patient with acute kidney injury (AKI) and potential pre-existing conditions such as hypertension or diabetes?

Management of Acute Kidney Injury in Pregnancy

Initial Risk Stratification and Monitoring

Pregnant women with AKI require immediate multidisciplinary management with intensive monitoring, as pregnancy-related AKI carries substantial maternal mortality (up to 14%) and fetal mortality (24% intrauterine death plus 16% early neonatal death), with the most common causes being preeclampsia, puerperal sepsis, and hemorrhage—all potentially preventable. 1, 2

Identify High-Risk Patients

Women at highest risk for pregnancy-related AKI include those with: 3, 1

• Pre-existing chronic kidney disease (40% risk of permanent worsening of renal function during pregnancy) 4
• Pre-existing hypertension or diabetes requiring baseline assessment of serum creatinine and urinary albumin-to-creatinine ratio 5
• Unbooked/emergency presentations (83.9% of AKI cases occur in unbooked patients) 2
• Lower socioeconomic status 1
• Advanced maternal age with comorbidities 6

Establish Baseline Renal Function

Measure serum creatinine and eGFR before conception or at first prenatal visit, recognizing that normal pregnancy decreases serum creatinine by approximately 0.4-0.5 mg/dL due to increased GFR, making standard AKI definitions challenging to apply. 6

Diagnostic Approach

Define AKI Using KDIGO Criteria

Apply the KDIGO definition: ≥50% increase in serum creatinine from baseline over a short period or urine output <0.5 mL/kg/hr for 6 hours. 5, 2 However, recognize that pregnancy-specific modifications may be needed given physiologic creatinine changes. 6

Determine the Etiology

The three most common causes of pregnancy-related AKI are preeclampsia (28%), puerperal sepsis (24%), and postpartum hemorrhage (20%). 1 Systematically evaluate for:

Pre-renal causes: 6

• Hyperemesis gravidarum (6.5% of cases) 2
• Hemorrhagic shock from PPH or placental abruption (16.1% of cases) 2
• Volume depletion

Intra-renal causes: 6

• Preeclampsia/eclampsia (22.6% of cases) - look for BP ≥140/90 mmHg, proteinuria, and end-organ dysfunction 2
• HELLP syndrome - hemolysis, elevated liver enzymes, low platelets
• Acute fatty liver of pregnancy (4.8% of cases) - typically third trimester with hypoglycemia, coagulopathy 2
• Thrombotic thrombocytopenic purpura (TTP) - fever, thrombocytopenia, microangiopathic hemolysis, neurologic symptoms
• Pregnancy-associated hemolytic uremic syndrome - typically postpartum
• Sepsis-related - puerperal sepsis (29%), septic abortion (9.7%), urosepsis (3.2%) 2

Post-renal causes: 6

• Obstructive uropathy from kidney stones
• Iatrogenic ureteral injury during cesarean section

Clinical Presentation

The majority of patients (72.6%) present with oliguria, followed by fever (40.3%), breathlessness (24.2%), and edema (22.6%). 2 Anuria occurs in 12.9% of severe cases. 2

Blood Pressure Management

Target Blood Pressure

Maintain BP between 110-140/85 mmHg in pregnant women with CKD or AKI. 4 This range balances maternal organ perfusion with prevention of hypertensive complications.

Antihypertensive Selection

First-line agents: 4

• Labetalol (preferred beta-blocker with alpha-blocking properties)
• Methyldopa (preferred based on long-term safety data) 5
• Nifedipine long-release (calcium channel blocker)

Absolutely contraindicated: 5, 4, 7

• ACE inhibitors - cause fetal toxicity and death
• ARBs - cause fetal toxicity and death
• These must be discontinued prior to conception or immediately upon pregnancy confirmation

Monitoring Frequency

• Weekly home blood pressure monitoring for all pregnant women with hypertension or CKD 4
• Monitor BP, kidney function, and proteinuria frequently with more intensive monitoring for those with pre-existing conditions 4

Fluid and Hemodynamic Management

Volume Resuscitation

Use isotonic crystalloids (normal saline or lactated Ringer's) rather than colloids for initial volume expansion. 5 Administer rapid crystalloid boluses while assessing response through: 7

• Urine output (target >0.5 mL/kg/hr)
• Mental status
• Peripheral circulation
• Jugular venous pressure

Vasopressor Use (If Indicated After Volume Resuscitation)

If hypotension persists after adequate volume resuscitation: 7

• Dopamine 2.5-5 μg/kg/min IV is preferred when renal hypoperfusion is present (improves renal perfusion at low doses)
• Dobutamine 2.5-10 μg/kg/min may be added if cardiac output is inadequate
• Avoid aggressive BP elevation as this can impair uteroplacental perfusion and cause fetal distress

Diuretic Use

Use diuretics cautiously and only in combination with other drugs, particularly when vasodilators exacerbate fluid retention. 4 Avoid in volume-depleted states.

Specific Treatment Based on Etiology

Preeclampsia/Eclampsia Management

• Administer magnesium sulfate for seizure prophylaxis
• Deliver the fetus - definitive treatment for preeclampsia
• Low-dose aspirin from first trimester until 36 weeks for prevention in high-risk women 4
• Screen regularly for preeclampsia, particularly in women with proteinuria 4

Sepsis Management

Puerperal sepsis is the leading cause of AKI-related maternal mortality (57% of deaths). 1 Management includes:

• Broad-spectrum antibiotics immediately after cultures
• Source control - drainage of abscesses, removal of retained products of conception
• Aggressive fluid resuscitation
• Monthly urinalysis and treatment of asymptomatic bacteriuria to prevent pyelonephritis 4

Hemorrhage Management

• Aggressive volume resuscitation with crystalloids
• Blood product transfusion (82.3% of AKI patients require transfusion) 2
• Surgical or interventional control of bleeding source
• Uterine artery embolization or hysterectomy if medical management fails

Thrombotic Microangiopathy Management

• TTP: Urgent plasma exchange
• Pregnancy-associated HUS: Supportive care, consider eculizumab if atypical HUS
• HELLP syndrome: Delivery of fetus, supportive care

Renal Replacement Therapy

Indications for Dialysis

Hemodialysis is required in 46-62.9% of pregnancy-related AKI cases. 1, 2 Standard indications apply:

• Severe hyperkalemia (>6.5 mEq/L)
• Metabolic acidosis (pH <7.1)
• Volume overload refractory to diuretics
• Uremic symptoms (pericarditis, encephalopathy)
• Blood urea nitrogen >100 mg/dL

Dialysis Prescription

For progressive renal disease in pregnancy, early dialysis with an aggressive prescription of approximately 36 hours per week appears to convey the best outcome. 4 This intensive approach optimizes both maternal and fetal outcomes.

Patient Positioning During Procedures

Use left lateral tilt positioning to prevent supine hypotension from inferior vena caval compression, which is crucial for preventing maternal hypotension and decreased placental perfusion. 8

Medication Management

Review All Medications

Before conception and during pregnancy, review all medications for teratogenicity potential. 4 Key considerations:

Discontinue prior to conception: 5, 4

• ACE inhibitors and ARBs (teratogenic)
• Statins (in some cases)
• Mycophenolate mofetil (teratogenic - stop at least 12 weeks before conception) 5

Adjust doses based on GFR: 4

• Consider GFR when dosing medications cleared by the kidneys
• Many antihypertensive drugs require dose adjustment

Safe to continue: 5

• Azathioprine
• Cyclosporine (monitor for hypertension and preeclampsia)
• Tacrolimus (monitor for hypertension and preeclampsia)
• Prednisolone (screen for gestational diabetes if >5 mg/day)

Diabetes Management in Pregnancy with AKI

For pregnant women with pre-existing diabetes and AKI: 5

• Target fasting glucose <95 mg/dL and 1-hour postprandial <140 mg/dL or 2-hour postprandial <120 mg/dL
• Target A1C <6% if achievable without significant hypoglycemia, otherwise <7%
• Use continuous glucose monitoring to achieve glycemic goals
• Screen for gestational diabetes in women on glucocorticoid treatment 5, 4

Delivery Planning

Timing of Delivery

Delivery should be performed for obstetric indications, taking into consideration the severity of maternal condition. 5 Consider preterm delivery if:

• Maternal condition worsens despite maximal medical therapy
• Fetal distress develops
• Severe preeclampsia/eclampsia unresponsive to treatment

Preparation for Preterm Delivery

Administer steroids 48 hours before delivery to accelerate fetal lung maturation if gestation is <34 weeks. 4

Mode of Delivery

In the study cohort: 2

• Normal vaginal delivery: 51.6%
• Lower segment cesarean section: 33.9%
• Dilation and evacuation: 11.3%
• Total hysterectomy: 3.2%

Cesarean section is not routinely recommended unless there are obstetric indications. 5

Maternal and Fetal Outcomes

Expected Maternal Outcomes

Complete renal recovery occurs in 77.4-80% of cases, with partial recovery in 6% and maternal mortality of 3.2-14%. 1, 2 The highest mortality is associated with:

• Puerperal sepsis (57% of deaths) 1
• Preeclampsia with severe features and multi-organ dysfunction (29% of deaths) 1
• Antepartum eclampsia with hepatorenal failure (14% of deaths) 1

Expected Fetal Outcomes

Fetal outcomes include: 2

• Live birth: 69.4%
• Intrauterine death: 8.1-24%
• Early neonatal death: 9.7-16%
• Abortion: 12.9%

Women with severe CKD have worse pregnancy outcomes, with higher rates of preeclampsia and preterm birth. 4

Long-Term Follow-Up

Post-Discharge Monitoring

Women with pregnancy-related AKI should be seen by a nephrologist early and within 6 months after delivery for postpartum kidney function review. 4 This is critical because:

• Patients with AKI are at increased risk for progressive CKD and ESRD 5
• Follow KDOQI CKD guidelines for patients at increased risk 5
• Monitor blood pressure, fluid status, proteinuria, and metabolic parameters at regular intervals 5

Counseling for Future Pregnancies

Women with incipient renal failure should be counseled that pregnancy may induce permanent worsening of renal function in 40% of patients. 4 Recommend:

• Achieving optimal glycemic and blood pressure control before conception
• Contraceptive plan to prevent pregnancy until goals are achieved 5
• Baseline assessment of renal function before subsequent pregnancies 4

Common Pitfalls to Avoid

• Do not discontinue ACE inhibitors/ARBs for minor creatinine increases (<30%) in non-pregnant patients, but these are absolutely contraindicated in pregnancy 5, 7
• Do not confuse small elevations in creatinine (up to 30%) with RAS blockers with true AKI in non-pregnant patients 5
• Do not delay dialysis - early aggressive dialysis improves outcomes 4
• Do not use excessive fluid administration that could lead to pulmonary edema, especially if cardiac dysfunction is present 7
• Do not position patients supine during procedures - use left lateral tilt 8
• Do not ignore unbooked/emergency presentations - these represent 83.9% of AKI cases 2