O23.01 Infections of kidney in pregnancy, first trimester

Name of the Condition

• Infections of kidney in pregnancy, first trimester
• ICD-10 Code: O23.01

Summary

Infections of the kidney during the first trimester of pregnancy, also known as pyelonephritis, involve bacterial infection of the renal parenchyma and collecting system. This condition is a serious complication of urinary tract infections (UTIs) and requires prompt medical attention to prevent maternal and fetal harm.

Causes

Pyelonephritis in the first trimester typically results from ascending bacterial infection, most commonly caused by Escherichia coli. Hormonal and anatomical changes during pregnancy, such as ureteral dilation and reduced urinary flow, increase susceptibility to UTIs that can progress to kidney infection.

Risk Factors

• Previous history of UTIs or pyelonephritis.
• Asymptomatic bacteriuria during pregnancy.
• Structural urinary tract abnormalities.
• Diabetes mellitus.
• Immunosuppression.
• Prolonged labor or catheterization.

Symptoms

• Fever, chills, or flank pain (unilateral or bilateral).
• Costovertebral angle tenderness.
• Nausea, vomiting, or abdominal pain.
• Dysuria, frequency, or urgency.
• Cloudy or foul-smelling urine.
• Fatigue or malaise.

Diagnosis

Diagnosis is confirmed through urinalysis (showing pyuria, bacteriuria, or positive nitrites), urine culture (to identify the causative organism and guide antibiotic therapy), and blood tests (to assess for systemic involvement). Imaging may be used if complications are suspected.

Treatment Options

• Antibiotics: Targeted therapy based on urine culture results to eliminate the infection.
• Hydration: Intravenous fluids to maintain renal function and support recovery.
• Monitoring: Close observation for maternal and fetal well-being, including vital signs and fetal heart rate.

Prognosis and Follow-Up

With prompt treatment, most cases resolve without long-term complications. Follow-up includes repeat urine cultures to ensure infection clearance and monitoring for recurrence, especially as pregnancy progresses.

Complications

• Preterm labor or delivery.
• Sepsis or septic shock.
• Acute kidney injury.
• Fetal growth restriction.
• Maternal anemia or hypertension.

Lifestyle & Prevention

• Maintain good hydration to support urinary tract health.
• Practice proper hygiene to reduce bacterial entry.
• Empty the bladder regularly to prevent stasis.
• Treat asymptomatic bacteriuria early in pregnancy.

When to Seek Professional Help

Seek immediate care for fever, severe flank pain, or signs of systemic infection (e.g., chills, dizziness). Prompt evaluation is critical to prevent complications.

Tips for Medical Coders

Document the trimester (first trimester) and confirm the infection involves the kidney. Ensure clinical notes specify the anatomical location and timing to support accurate coding.