A 36-year-old primigravida at 26 weeks gestation comes to the office due to painful urination. She has had urinary frequency since her first month of pregnancy, but a week ago, she developed dysuria. The patient has also had chills, fatigue, and radiating back pain for the past 2 days. She has intermittent, nonpainful contractions but no vaginal bleeding or leakage of fluid. Fetal movement is normal. Three years ago, the patient was treated for pyelonephritis. She has no chronic medical conditions and has had no surgeries. Temperature is 38.1 C (100.6 F), blood pressure is 110/60 mm Hg, and pulse is 115/min. Fundal height is 26 cm and fetal heart tones are 170/min. There is tenderness over the right costovertebral angle. The uterus is nontender and the cervix is closed. Urinalysis is positive for leukocyte esterase and blood; a urine culture is collected. Which of the following is the best next step in management of this patient?
Pyelonephritis in pregnancy | |
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This patient has acute pyelonephritis, an upper urinary tract infection. Pyelonephritis is more common in pregnancy, likely due to the increased risk for recurrent, asymptomatic bacteriuria and physiologic maternal immunosuppression. In addition, progesterone-induced ureteral dilation, ureteral valve laxity, and bladder compression from the gravid uterus may facilitate bacterial ascent from the lower urinary tract.
Patients with pyelonephritis can have preceding symptoms of cystitis (eg, dysuria) followed by fever, chills, back pain, maternal and fetal tachycardia, and costovertebral angle tenderness. Diagnosis is confirmed with urinalysis (eg, leukocyte esterase, blood), as in this patient. Urine culture is also performed.
Pregnant patients with pyelonephritis are at high risk for severe maternal (eg, sepsis, acute respiratory distress syndrome, preterm labor) and fetal (eg, preterm birth) complications. Therefore, these patients require inpatient admission and empiric intravenous antibiotics (eg, ceftriaxone) while urine culture results are pending. Once patients remain afebrile for 24-48 hours and have symptomatic improvement, they may be transitioned to oral antibiotics based on urine culture results and antibiotic sensitivity testing (Choice C).
(Choices A, D, and E) Abdominal and renal imaging (eg, CT scan of the abdomen and pelvis, renal ultrasonography) can be used to diagnose nephrolithiasis, which may also present with radiating back pain and hematuria. However, this patient's fever and history of pyelonephritis make acute pyelonephritis more likely, and imaging is not required for diagnosis in patients with a classic clinical presentation. In addition, imaging in pregnant women typically reveals physiologic hydronephrosis that could be mistaken for pathology and lead to unnecessary interventions (eg, ureteral stent placement). Therefore, imaging is reserved for patients whose condition does not improve within 48-72 hours of intravenous antibiotics. In these patients, renal ultrasound is performed to evaluate for nephrolithiasis (which, if limited to small, distal ureteral caliculi, can be treated with intravenous fluids and tamsulosin to facilitate passage) or renal abscess (which typically requires drainage).
Educational objective:
Acute pyelonephritis in pregnancy typically presents with fever, maternal and fetal tachycardia, and costovertebral angle tenderness. Because of the high risk for severe maternal and fetal complications (eg, sepsis, preterm delivery), management is with inpatient admission and empiric intravenous antibiotics (eg, ceftriaxone).