PYELONEPHRITIS DURING PREGNANCY

Predisposing Factors and Clinical Picture of Pyelonephritis

Predisposing Factors

Pyelonephritis is a type of urinary tract infection (UTI) that affects the kidneys. Several predisposing factors can increase the risk of developing pyelonephritis:

1. Anatomical Abnormalities: Structural abnormalities in the urinary tract, such as renal stones, ureteral strictures, or congenital anomalies, can obstruct urine flow and promote infection.

2. Female Gender: Women are more prone to UTIs due to shorter urethras and proximity of the urethra to the anus.

3. Pregnancy: Hormonal changes and anatomical alterations during pregnancy can lead to urinary stasis and increased risk of infection.

4. Diabetes Mellitus: Diabetes can impair immune function and alter urinary tract defenses, making individuals more susceptible to infections.

5. Immunocompromised States: Conditions such as HIV/AIDS, cancer treatments, or use of immunosuppressive medications can increase vulnerability to infections.

6. Catheterization: The presence of urinary catheters increases the risk of introducing bacteria into the urinary tract.

7. Previous History of UTIs: A history of recurrent UTIs may predispose individuals to pyelonephritis.

Organisms

The most common organisms responsible for pyelonephritis include:

• Escherichia coli (most prevalent)
• Klebsiella pneumoniae
• Proteus mirabilis
• Enterococcus faecalis
• Pseudomonas aeruginosa (especially in complicated cases)

Clinical Picture

The clinical presentation of pyelonephritis typically includes:

1. Fever and Chills: Patients often present with high fever (>38°C) accompanied by chills.
2. Flank Pain: Unilateral or bilateral flank pain is common due to inflammation around the kidneys.
3. Dysuria and Urgency: Patients may experience painful urination (dysuria), increased frequency, and urgency.
4. Nausea and Vomiting: Gastrointestinal symptoms may accompany systemic illness.
5. Malaise and Fatigue: General feelings of unwellness are common.

In pregnant women, symptoms may be less pronounced but still include fever, flank pain, and dysuria.

Complications

Complications associated with pyelonephritis can include:

1. Renal Abscesses: Pockets of pus that form within the kidney tissue.
2. Sepsis: A severe systemic response to infection that can lead to organ failure.
3. Chronic Kidney Disease: Recurrent infections can lead to long-term kidney damage.
4. Preterm Labor or Low Birth Weight in Pregnant Women: Infection during pregnancy can adversely affect fetal health.

Differential Diagnosis

Differential diagnoses for pyelonephritis include:

1. Acute Cystitis: Lower urinary tract infection without kidney involvement.
2. Kidney Stones (Nephrolithiasis): Can cause similar flank pain but usually presents with hematuria.
3. Appendicitis: Right-sided abdominal pain could mimic renal colic or pyelonephritis.
4. Ectopic Pregnancy: In females of childbearing age presenting with unilateral pain.
5. Pelvic Inflammatory Disease (PID): May present with abdominal pain and fever in sexually active women.

History Taking from Pregnant Women with Urinary Symptoms

When taking a history from pregnant women presenting with urinary symptoms, consider asking about:

1. Duration and nature of symptoms (e.g., dysuria, frequency).
2. Associated symptoms (e.g., fever, chills).
3. Previous history of UTIs during pregnancy or prior pregnancies.
4. Any recent catheterization or surgical procedures involving the urinary tract.
5. Medical history including diabetes or immunocompromised states.
6. Obstetric history including gestational age and any complications in current or previous pregnancies.

Investigations

For diagnosing pyelonephritis, appropriate investigations include:

1. Urinalysis: To check for leukocytes, nitrites, blood, and bacteria.
2. Urine Culture and Sensitivity Testing: To identify causative organisms and determine antibiotic susceptibility.
3. Blood Tests:
   • Complete Blood Count (CBC): To assess for leukocytosis indicating infection.
   • Blood Cultures if sepsis is suspected.
4. Imaging Studies (if indicated):
   • Ultrasound or CT scan if there is suspicion for abscess formation or obstruction.

Antibiotic Selection

Initial empirical antibiotic therapy for uncomplicated pyelonephritis typically includes:

1. For outpatient treatment:
   • Trimethoprim-sulfamethoxazole
   • Nitrofurantoin
   • Fosfomycin
2. For inpatient treatment:
   • Ceftriaxone
   • Piperacillin-tazobactam
   • Meropenem (for resistant organisms)

In pregnant women specifically, it is crucial to choose antibiotics that are safe during pregnancy; options like ceftriaxone or ampicillin are commonly used due to their safety profile.