Urinary tract infections during pregnancy


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Urinary tract infections during pregnancy

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Urinary tract infections during pregnancy

  1. 1. Urinary tract infections during pregnancy Prof Aboubakr Elnashar Benha University Hospital Aboubakr Elnashar
  2. 2. Definitions Urinary tract infection An asymptomatic: 100,000 organisms/ml of urine Symptomatic: 100 organisms/mL of urine with accompanying pyuria (>7WBCs]/mL) Diagnosis should be supported by a positive culture, particularly with vague symptoms. Risks: pyelonephritis, preterm birth, low birth weight, increased perinatal mortality. Aboubakr Elnashar
  3. 3. Asymptomatic bacteriuria 100,000 organisms/mL in 2 consecutive urine samples in the absence of symptoms. Pregnant: 2.5-11% Nonpregnant: 3-8% Aboubakr Elnashar
  4. 4. Acute cystitis inflammation of the bladder {bacterial or nonbacterial causes (eg, radiation or viral infection)}. 1% of pregnant patients Aboubakr Elnashar
  5. 5. Acute pyelonephritis 2% of all pregnancies. 2% during the 1st trimester 52% during the 2nd trimester 46% in the 3rd trimester. Aboubakr Elnashar
  6. 6. Epidemiology UTIs in women: 14 times more frequent than in men. 1. The urethra is shorter 2. lower 1/3 of the urethra is continually contaminated with pathogens from the vagina and the rectum 3. Women tend not to empty their bladders as completely as men do 4. Urogenital system is exposed to bacteria during intercourse Aboubakr Elnashar
  7. 7. Increase the frequency (UTIs) in pregnant women. 1. Difficult hygiene due to a distended pregnant belly 2. Immunocompromised Aboubakr Elnashar
  8. 8. 3. Hormonal and mechanical changes: urinary stasis and vesicoureteral reflux urinary stasis {progesterone-induced ureteral smooth muscle relaxation} urinary retention {weight of the enlarging uterus} Loss of ureteral tone combined with increased urinary tract volume: urinary stasis: dilatation of the ureters, renal pelvis, and calyces. more common on right side (86% of cases) more pronounced on right (15 mm vs 5 mm). begin at10 w and worsens throughout pregnancy. Aboubakr Elnashar
  9. 9. 4. Glycosuria and aminoaciduria Glycosuria {impaired resorption by the collecting tubule and loop of Henle of the 5% of the filtered glucose, which escapes proximal convoluted tubular resorption}. Selective aminoaciduria {unknown} although its presence has been postulated to affect the adherence of Escherichia coli to the urothelium. Aboubakr Elnashar
  10. 10. Asymptomatic bacteriuria Risk factors 5-fold poor patients doubled in sickle cell trait. Other risk factors DM Neurogenic bladder retention History of vesicoureteral reflux previous renal transplantation history of previous UTIs multiple pregnancy prolonged hospitalization Aboubakr Elnashar
  11. 11. Symptomatic UTI: 2.3%. increases with maternal age. Aboubakr Elnashar
  12. 12. Pathophysiology Infections result from ascending colonization of the urinary tract, primarily by existing vaginal, perineal, and fecal flora. Aboubakr Elnashar
  13. 13. Etiology Infection E coli : most common cause of UTI, 80-90% originates from fecal flora colonizing the periurethral area: ascending infection. Other pathogens: Klebsiella pneumoniae (5%) Proteus mirabilis (5%) Enterobacter species (3%) Staphylococcus saprophyticus (2%) Group B beta-hemolytic Streptococcus (GBS; 1%) Proteus species (2%) Aboubakr Elnashar
  14. 14. S saprophyticus, an aggressive organism: UUTI: persistent or recurrent Urea-splitting bacteria Proteus, Klebsiella, Pseudomonas, and coagulase negative Staphylococcus: alkalinize the urine: stones. Chlamydial infections :sterile pyuria (30% of atypical pathogens). Aboubakr Elnashar
  15. 15. GBS colonization Intrapartum transmission: neonatal GBS pneumonia, meningitis, sepsis, and death. Guidelines universal vaginal and rectal screening in all pregnant women at 35-37 W rather than treatment based on risk factors. Aboubakr Elnashar
  16. 16. Preeclampsia predisposed to UTI. UTI 16.2% in normotensive 27.3% in mild PET 35.9% in severe PET {underlying renal damage weakens patients’ systemic defense mechanisms against ascending infection}. Aboubakr Elnashar
  17. 17. Cesarean delivery :UTI (2.7-fold), confounded by bladder catheterization or PROM). symptomatic UTI: 9.3% asymptomatic bacteriuria: 7.6%. Aboubakr Elnashar
  18. 18. Beta streptococci bacteriuria Indicate higher colonization count than revealed by vaginal or rectal culture.  immediate treatment intrapartum antibiotic prophylaxis : preterm labor: controversial. Aboubakr Elnashar
  19. 19. Complications UTI during pregnancy is independently: IUGR Preeclampsia preterm delivery CS. Asymptomatic bacteruria acute cystitis (40%) pyelonephritis (30%). risk of preterm birth: 1.8-2.3 Acute cystitis low birth weight and preterm delivery Pyelonephritis: 15-50% of cases. Aboubakr Elnashar
  20. 20. Untreated upper UTIs low birth weight, prematurity, premature labor hypertension, preeclampsia maternal anemia, and amnionitis. Aboubakr Elnashar
  21. 21.  Other complications: 1. Perinephric cellulitis and abscess, Septic shock (rare) 2. Renal dysfunction (usually transient, but as many as 25% of pregnant women with pyelonephritis have a decreased glomerular filtration rate) 3. Hematologic dysfunction (common but seldom of clinical importance) 4. Pulmonary injury: 2% of women with severe pyelonephritis during pregnancy have evidence of pulmonary injury due to systemic inflammatory response syndrome and respiratory insufficiency. Endotoxins that alter alveolar-capillary membrane permeability are produced; subsequently, pulmonary edema and acute respiratory distress syndrome develop. • Aboubakr Elnashar
  22. 22. 5. Hypoxic fetal events {maternal complications of infection that lead to hypoperfusion of the placenta} 6. PTL: increased infant morbidity and mortality Aboubakr Elnashar
  23. 23. Diagnosis I. History  Cystitis 1. Dysuria most significant symptom 2. Other symptoms: Frequency Urgency suprapubic pain hematuria in the absence of systemic symptoms. The usual complaints of increased frequency, nocturia, and suprapubic pressure are not particularly helpful, {most pregnant women experience these as a result of increased pressure from the growing uterus, expanding blood volume, increased glomerular filtration rate, and increased renal blood flow.} Aboubakr Elnashar
  24. 24. Pyelonephritis: 1. Fever (>38°C) 2. Shaking chills 3. Anorexia, nausea, and vomiting. 4. Right-side flank pain is more common than left- side or bilateral flank pain. 5. Lower UTI symptoms: common but not universal. 6. ±hypothermia (as low as 34°C). Aboubakr Elnashar
  25. 25. II. Physical Examination Pelvic examination: recommended in all symptomatic patients (with the exception 3rd trimester patients with bleeding) to rule out vaginitis or cervicitis Aboubakr Elnashar
  26. 26. Asymptomatic bacteriuria No physical findings are typically present. Symptoms may arise intermittently, only to be overlooked because of lack of persistence or severity. Cystitis Tenderness. Aboubakr Elnashar
  27. 27. Pyelonephritis 1. Fever (usually >38°C) an ill appearance. 2. Flank tenderness on the right side in more than half of patients, bilaterally in one fourth on the left side in one fourth. 3. Assessment of the FHR {maternal fever} FHR: elevated to more than 160 beats/min. Aboubakr Elnashar
  28. 28. Investigations Blood Studies CBC Serum electrolytes Blood urea nitrogen (BUN) Serum creatinine Aboubakr Elnashar
  29. 29. Urine Studies Urine specimen collection All pregnant patients urinalysis and culture (Screening) in 1st prenatal visit or at 12-16w. identify asymptomatic bacteriuria, as well as those with other concerning findings such as glucosuria. Midstream clean catch With one hand, spread the labia With the other hand, use a castile soap–moistened towelette to wipe the urethral meatus downward toward the rectum, then discard the towelette Void the initial portion of the bladder contents into the toilet Catch the middle portion of the bladder contents in the sterile collection container, while keeping the labia spread with the first hand Aboubakr Elnashar
  30. 30. > 1 organism in a culture: contaminated specimen. The specimen should be sent for evaluation as soon as possible {Specimens that are allowed to sit at room temperature may have falsely elevated colony counts}. Refrigerate the specimen at 4°C if it cannot be transported immediately. Aboubakr Elnashar
  31. 31. Urine culture Standard method for evaluating for UTI during pregnancy. Indications : Recurrent UTI Pyelonephritis Failure to respond to initial treatment History of recent instrumentation Hospital admission Aboubakr Elnashar
  32. 32. Positive culture Two consecutive voided specimens with isolation of the same bacterial strain, at a colony count of 100,000 colony- forming units (CFUs) per milliliter or higher OR A single catheterized specimen yielding a colony count of at least 100 CFU/mL Contamination Counts lower than 100,000 CFU/mL, with 2 or more organisms Patients with pyelonephritis often have white blood cell (WBC) casts. Culture results can be used to identify specific organisms and antibiotic sensitivities Cultures yielding significant growths of mixed organisms should prompt a search for underlying renal calculi. Aboubakr Elnashar
  33. 33. Urinalysis Positive results for nitrites, leukocyte esterase, WBCs, RBCs, and protein: suggest UTI. Bacteria found in the specimen can help with the diagnosis. Urinalysis: Specificity (ability to identify negtive results): 97-100% Sensitivity (ability to identify positive results).: 25-67%=false-positive rate is very high 1-2 bacteria in an unspun catheterized specimen or >20 bacteria /HPF in spun urine correlate closely with bacterial colony counts >100,000 CFU/mL on a urine culture. Aboubakr Elnashar
  34. 34. Dipstick testing for nitrites & leukocyte esterase in the evaluation of asymptomatic bacteriuria: Sensitivity: 50% to 92% and Specificity: 86% to 97%. In the evaluation of symptomatic: useful and inexpensive. leukocyte esterase test may be unreliable in patients with low-level pyuria (5-20 WBCs/HPF). The addition of protein and blood increases the sensitivity and specificity of the test in the evaluation of UTI. Aboubakr Elnashar
  35. 35. Nitrite dipstick testing may be a reasonable and cost-effective screening strategy for women who otherwise may not undergo screening for bacteriuria, as is often the case in developing countries. Aboubakr Elnashar
  36. 36. Urine cytology: useful adjunct in detecting UUTIs. Clumping WBCs and WBC casts: pyelonephritis. RBC casts: acute glomerulonephritis Oval fat bodies and fatty casts: Membranous glomerulonephritis. Renal involvement: proteinuria. Nephrotic syndrome: high proteinuria (>3.5 g/24 h), edema, hypercholesterolemia, and hypoalbuminemia; can be confused with preeclampsia. Aboubakr Elnashar
  37. 37. Other tests An antistreptolysin-O (ASO) titer: greater than 200 Todd units: recent group A streptococcal infection; however, as many as 20% of patients with acute glomerulonephritis have ASO titers within the reference range. The sulfosalicylic acid (SSA) test: measures urine turbidity when a small amount of aspirin is added to the urine specimen. A finding of +2 to +4 suggests bacteriuria. Aboubakr Elnashar
  38. 38.  Renal Ultrasonography and limited Intravenous Pyelography (IVP) Indications 1. An anatomic abnormality or renal disease is suspected 2. Patients with suspected pyelonephritis who are not responsive to appropriate antibiotic therapy after 48-72 h 3. Recurrent UTI or symptoms that suggest nephrolithiasis, if the benefits of a definitive diagnosis outweigh the minor risk of radiation Aboubakr Elnashar
  39. 39. Renal US is often performed initially, but the findings are often inconclusive. A limited IVP (kidneys-ureters-bladder [KUB] with a 30-min shot after contrast injection) can be helpful in delineating the site of the obstruction. Aboubakr Elnashar
  40. 40. The total dosage of ionizing radiation should not exceed 3-5 cGy during the course of pregnancy. Of particular concern is radiation delivered during 1st trimester, during organogenesis (especially days 11-56). A limited IVP can deliver 0.4-1 cGy. Radiation doses >5 cGy: increased likelihood of benign and malignant tumors in the child after birth. No patient should receive more than 10-14 cGy. Centigray: a unit of absorbed radiation dose equal to one hundredth of a gray, or 1 rad. Aboubakr Elnashar
  41. 41. Urolithiasis unique problem in pregnant women. Diagnosis: Pyelonephritis have many symptoms in common (eg, hematuria, flank pain, shaking chills, anorexia). usually not associated with fever, except in patients with concomitant pyelonephritis. Confusion about the diagnosis of urolithiasis, pyelonephritis, or both is an indication for obtaining imaging studies. Aboubakr Elnashar
  42. 42. Treatment initially conservative {50-67% diagnosed during pregnancy pass spontaneously} Antibiotic Hydration Analgesics (usually narcotics, which are class C agents in pregnancy). Anti-inflammatory {oligohydramnios, premature closure of the patent ductus arteriosus, or both} should be avoided if possible. Aboubakr Elnashar
  43. 43.  If ultrasonography reveals a stone, ultrasound- guided cystoscopic passage of a ureteral stent may relieve ureteral colic. In some cases (eg, pyonephrosis with an obstructing stone), percutaneous nephrostomy can be useful. Cystoscopic extraction of a distal ureteral stone (with fluoroscopic guidance) should be used sparingly because of the risk of ionizing radiation to the fetus. Aboubakr Elnashar
  44. 44. Treatment Bacteriuria and cystitis 1. Administration of appropriate antibiotics 2. Administration of fluid if the patient is dehydrated 3. Admission if any indication of complicated UTI exists Aboubakr Elnashar
  45. 45. Behavioral methods To ensure good hygiene and reduce bacterial contamination of the urethral meatus: preventing inadequate treatment and recurrent infection. 1. Avoid baths 2. Wipe front-to-back after urinating or defecating 3. Wash hands before using the toilet 4. Use washcloths to clean the perineum 5. Use liquid soap to prevent colonization from bar soap 6. Clean the urethral meatus first when bathing 7. Changes in coital patterns (eg, position, frequency, postcoital antibiotics) can offset recurrence in at-risk individuals. Several non-pharmacological manoeuvres may help prevent recurrent infec- tion in those women troubled by UTIs in pregnancy. These include: Increasing fluid intake. This ensures frequent voiding and a high-volume dilute urine, all of which reduce the risk of symptomatic infection Emptying the bladder following sexual intercourse. This 'washes away' organisms massaged up the urethra from the perineum into the bladder during coitus, before they have a chance to replicate in urine within the bladder Double voiding (to ensure no residual urine is left in the bladder following micturition) The perineum should be cleaned from 'front to back' following defaecation to minimise the risk of bowel organisms colonising the urethra. Aboubakr Elnashar
  46. 46. Aboubakr Elnashar
  47. 47. Antibiotic therapy Oral antibiotics are the treatment of choice for asymptomatic bacteriuria and cystitis. William (2010) Single-dose treatment Amoxicillin 3 g Ampicillin 2 g Cephalosporin 2 g Nitrofurantoin 200 mg Trimethoprim-sulfamethoxazole 320/1600 mg Aboubakr Elnashar
  48. 48. 3-day course Amoxicillin 500 mg three times daily Ampicillin 250 mg four times daily Cephalosporin 250 mg four times daily Ciprofloxacin 250 mg twice daily Levofloxacin 250 mg daily Nitrofurantoin 50 to 100 mg four times daily; 100 mg twice daily Trimethoprim-sulfamethoxazole 160/800 mg two times daily Other Nitrofurantoin 100 mg four times daily for 10 days Nirofurantoin 100 mg twice daily fo 7 days Nitrofurantoin 100 mg at bedtime for 10 days Aboubakr Elnashar
  49. 49. Treatment failures Nitrofurantoin 100 mg four times daily for 21 days Suppression for bacterial persistence or recurrence Nitrofurantoin 100 mg at bedtime for remainder of pregnancy Aboubakr Elnashar
  50. 50. The resistance of E coli to ampicillin and amoxicillin is 20-40%; accordingly, these agents are no longer considered optimal for treatment of UTIs caused by this organism. Fosfomycin, a phosphonic acid derivative, is useful in the treatment of uncomplicated UTIs caused by susceptible strains of E coli and Enterococcusspecies. Fosfomycin is a category B agent in pregnancy (ie, fetal risk is not confirmed by human studies but has been shown in some animal studies). Aboubakr Elnashar
  51. 51. Although 1-, 3-, and 7-day antibiotic courses have been evaluated, 10-14 days of treatment is usually recommended to eradicate the offending bacteria. Treatment for 3 days is sufficient for asymptomatic bacteriuria. Regular urine cultures should be taken following treatment to ensure eradication of the organism. About 15% of women will have recurrent bacteriuria during their pregnancy and require a second course of antibiotics. Antibiotics should be continued for 5-7 days in cystitis Cephalexin, trimethoprim-sulfamethoxazole, and amoxicillin single dose is as effective as a 3- to 7- day course of therapy, but the cure rate is only 70%. Aboubakr Elnashar
  52. 52. A test-for-cure urine culture should show negative findings 1-2 w after therapy. A nonnegative culture result is an indication for a 10- to 14-day course of a different antibiotic, followed by suppressive therapy (eg, nitrofurantoin 50 mg at bedtime) until 6 w postpartum. Aboubakr Elnashar
  53. 53. Acute Pyelonephritis Hospitalization Investigations and monitoring Urine and blood cultures CBC, serum creatinine, and electrolytes Monitor vital signs frequently, urinary output, consider indwelling catheter Establish urinary output to 50 mL/hr with IVF Chest radiograph if there is dyspnea or tachypnea Aboubakr Elnashar
  54. 54.  IV antibiotics IV fluids with caution. Patients with pyelonephritis can become dehydrated {nausea and vomiting} and need IV hydration. However, they are at high risk for the development of pulmonary edema and ARDS Fever: antipyretics (preferably, acetaminophen) Nausea and vomiting: antiemetics. Most antiemetics can be used for adverse effects caused by antibiotics, but doxylamine, Emetrol (Wellspring, Sarasota, FL; pregnancy class A), dimenhydrinate, and metoclopramide (pregnancy class B) are preferred. Aboubakr Elnashar
  55. 55. Follow up Repeat hematology and chemistry studies in 48 h Change to oral antimicrobials when afebrile Discharge when afebrile 24 h, consider antibiotic for 7 to 10 days Repeat urine culture 1 to 2 weeks after antibiotic completed Aboubakr Elnashar
  56. 56. Risk of PTL must be evaluated and treated early in the course of admission. {Pyelonephritis places the patient at risk for spontaneous abortion in early pregnancy and for preterm labor after 24 w}. Aboubakr Elnashar
  57. 57. Antibiotic selection IV administration of cephalosporins or gentamicin. Antibiotic selection should be based on urine culture sensitivities, if known. Often, therapy must be initiated on an empirical basis, before culture results are available. Institution-specific drug resistances should also be considered before a treatment antibiotic is chosen. E coli infection resistance to Ampicillin: 28-39%. Trimethoprim-sulfamethoxazole: 31% First-generation cephalosporins: 9-19%. Aboubakr Elnashar
  58. 58. Some antibiotics should not be used during pregnancy:  Tetracyclines (adverse effects on fetal teeth and bones and congenital defects) Chloramphenicol (gray syndrome) Trimethoprim in the first trimester (facial defects and cardiac abnormalities) Sulfonamides (hemolytic anemia in mothers with glucose-6-phosphate dehydrogenase [G6PD] deficiency, jaundice, and kernicterus) in the third trimester. Aboubakr Elnashar
  59. 59. Fluoroquinolones: are contraindicated in pregnancy. Although in utero exposure is not an indication for termination, fetal exposure to fluoroquinolones has been associated with myelomeningocele, hydrocephaly, hypospadias, maldescended testes, inguinal hernia, bilateral hip dysplasia, and atrial septal defects. That the anomalies seem not to follow a particular pattern may be reassuring; however, a causal relation cannot be excluded. Aboubakr Elnashar
  60. 60. Nitrofurantoin safe and effective; however, poor tissue penetration has limited its use in pyelonephritis. In the past, nitrofurantoin was completely avoided in the third trimester because of hemolytic effects on the newborn. Currently, restriction of this agent is limited to the last several weeks of pregnancy. Use during this period can cause hemolytic anemia in the fetus or neonate as a consequence of their immature erythrocyte enzyme systems (glutathione instability). Nitrofurantoin is also safe and effective for once- daily prophylactic therapy during pregnancy. Aboubakr Elnashar
  61. 61. Macrolides not first-line agents for UTI in pregnancy. However, they are well tolerated by mother and fetus. Aboubakr Elnashar
  62. 62. Surgical treatment Rarely indicated, unless one of the pathologic causes listed in the differential diagnoses is suspected. In patients with urethral or bladder diverticulum, bladder stones, urethral syndrome, lower urinary tract trauma, interstitial cystitis, or bladder cancer, cystoscopy may aid in establishing the diagnosis. A retrograde stent or a percutaneous nephrostomy tube should be placed to relieve ureteral colic or decompress an obstructed infected collecting system. More invasive procedures, such as ureteroscopic stone extraction,are rarely indicated. Aboubakr Elnashar
  63. 63. Extracorporeal shock wave lithotripsy (ESWL) is contraindicated in pregnancy. In the rare patient for whom invasive surgical therapy is indicated, the operation should be planned for the second trimester. Surgical intervention during the first trimester is associated with miscarriage; surgery in the third trimester is associated with preterm labor. Urgent surgical intervention in the third trimester should coincide with delivery of the fetus. Aboubakr Elnashar
  64. 64. Conclusion Urinary tract infection is more common in pregnancy. Asymptomatic bacteriuria should be treated because there is a significant risk of acute pyelonephritis. Acute pyelonephritis increases the risk of premature labour. Acute pyelonephritis should be managed in hospital with i.v, antibiotics. Once antibiotic treatment has rendered the urine sterile, regular MSU specimens are necessary to exclude reinfection. Aboubakr Elnashar
  65. 65. Amoxycillin and cephalosporins are appropriate antibiotics for the treatment and prevention of UTI in pregnancy. Gentamicin may be required for severe or resistant infections. Investigations in cases of pyrexia and suspected acute pyelonephritis should include blood cultures, a full blood count, renal function and a renal US. Aboubakr Elnashar
  66. 66. Thank you Aboubakr Elnashar Aboubakr Elnashar