What is leptospirosis and what are the maternal and fetal risks and recommended management in pregnant patients?

Leptospirosis in Pregnancy: Definition, Risks, and Management

What is Leptospirosis?

Leptospirosis is a bacterial zoonotic infection caused by pathogenic Leptospira species, transmitted through contact with urine-contaminated water or soil from infected animals, presenting as a biphasic illness with potentially life-threatening complications including pulmonary hemorrhage, renal failure, and hepatic dysfunction. 1, 2, 3

• The disease is acquired by direct contact with infected animals or indirect contact with water/soil contaminated by urine from infected animals, with leptospires entering through mucous membranes or skin abrasions 4, 3
• Clinical presentation includes a characteristic triad: sudden onset fever with severe myalgia, conjunctival suffusion (a distinctive finding), and exposure history to contaminated water or flooding 1
• The illness follows a biphasic pattern with an initial bacteremic phase (4-7 days) followed by an immune phase featuring fever, severe muscle pain, and potential organ failure 1, 5, 3

Maternal and Fetal Risks in Pregnancy

Maternal Complications

Pregnant women with leptospirosis face severe maternal morbidity and mortality risks, with the disease causing multisystem organ failure including hepatorenal syndrome, pulmonary hemorrhage with ~50% mortality, and hemorrhagic manifestations due to capillary fragility. 6, 1, 7

• Weil's disease (severe leptospirosis) presents with jaundice, hepatorenal syndrome, and hemorrhagic manifestations, with death potentially occurring within 72 hours of pulmonary hemorrhage onset 1, 7
• Leptospirosis-associated pulmonary hemorrhagic syndrome (LPHS) carries approximately 50% mortality and manifests as coughing, chest pain, dyspnea, and massive pulmonary hemorrhage 7
• As with other severe systemic infections, preterm labor may occur in pregnant women with leptospirosis 6

Fetal and Neonatal Risks

Leptospirosis in pregnancy can cause transplacental transmission to the fetus, resulting in fetal infection, nonimmune hydrops fetalis, fetal death, and neonatal infection. 6

• Leptospirosis has been reported as a cause of nonimmune hydrops fetalis (NIHF) through mechanisms including fetal anemia, anoxia, endothelial cell damage, increased capillary permeability, and myocarditis 6
• Transplacental transmission of Leptospira to the fetus can occur, with risk of neonatal infection requiring treatment 6
• The infection can lead to stillbirth, miscarriage, and intrauterine growth restriction through severe systemic maternal illness 6

Management Algorithm for Pregnant Women

Immediate Treatment Protocol

Start antibiotics immediately upon clinical suspicion without waiting for laboratory confirmation, as delays can lead to life-threatening complications. 1, 5

For Mild to Moderate Disease:

• Doxycycline is contraindicated in pregnancy due to permanent tooth discoloration in the developing fetus, particularly with repeated or long-term exposure 6
• Alternative oral therapy: Penicillin antibiotics are the treatment of choice during pregnancy 6, 1

For Severe Disease (Preferred Regimen):

• Amphotericin B remains the treatment of choice in pregnancy, with lipid formulations being safe 6
• Penicillin G sodium 1.5 million units IV every 6 hours for 7 days 1
• Alternative: Ceftriaxone 1-2 g IV daily for 7 days (equally effective as penicillin with once-daily dosing advantage) 1
• Parenteral administration is preferred due to frequent inability of pregnant women to tolerate oral medications and decreased GI absorption during pregnancy 6

Hospitalization and Monitoring

Hospitalization should be strongly considered for pregnant women with leptospirosis, particularly those with pneumonic manifestations or in second/third trimester, to facilitate parenteral antimicrobial administration and monitoring for preterm labor and maternal hemorrhage. 6

• Monitor continuously for pulmonary complications: listen for crepitations/crackles, monitor respiratory rate, and watch for dyspnea 5
• Assess perfusion parameters: warm extremities, capillary refill <2-3 seconds, urine output >0.5 mL/kg/hour, normal mental status 5
• Standard guidelines for maternal sepsis should be followed when managing leptospirosis with associated signs of sepsis 6

Fluid Management Considerations

• Administer crystalloid solutions intravenously as primary resuscitation fluid, avoiding oral rehydration due to systemic disease nature and risk of rapid deterioration 5
• Give fluid boluses cautiously (250-500 mL) and reassess after each bolus for signs of improved perfusion versus pulmonary complications 5
• Stop fluids immediately if crepitations develop, respiratory distress worsens, or perfusion normalizes, as this indicates fluid overload or onset of pulmonary hemorrhage 5

Preterm Labor Management

• Administration of corticosteroids to promote fetal lung maturity may be considered if preterm labor occurs, in accordance with ACOG guidelines and as deemed appropriate by the clinical care team 6

Neonatal Management

If the newborn shows evidence of infection, treatment with amphotericin B deoxycholate 1.0 mg/kg daily for 4 weeks is recommended. 6

Critical Pitfalls to Avoid

• Never delay treatment while awaiting laboratory confirmation - serologic testing may not be positive until 6-10 days after symptom onset, which is too late for preventing severe complications 1, 5
• Do not use azole antifungals (fluconazole, itraconazole) during pregnancy - these are teratogenic and embryotoxic in animals, with long-term fluconazole associated with congenital anomalies 6
• Avoid doxycycline throughout pregnancy - causes permanent tooth discoloration in developing fetus 6
• Do not underestimate disease severity based on modest transaminase elevations - patients can rapidly progress to critical illness despite initially mild laboratory findings 1
• Never ignore exposure history - occupational or recreational water contact, flooding exposure, or animal contact in endemic areas should immediately raise clinical suspicion 1, 5
• Do not add potassium to initial hydration fluids despite expected hypokalemia - wait for laboratory confirmation and renal function assessment 5

Prophylaxis Considerations

• Prophylaxis is generally not recommended for routine flood exposure in pregnant women due to doxycycline contraindication 8, 5
• Primary prevention focuses on avoiding contact with contaminated water, especially during floods, and using protective equipment during unavoidable exposures 8
• For children under 8 years (relevant for pediatric counseling), doxycycline is contraindicated with no established alternative prophylaxis 8, 5