UTI in pregnancy

1. *Definition
A urinary tract infection (UTI) is a bacterial infection that affects any part of the urinary tract.
Most common in pregnancy. UTIs may be referred to as cystitis or pyelonephritis, or ASB
terms that refer to the lower or upper urinary tract infection, for pyelonephritis and cystitis
respectively.
The terms bacteriuria and candiduria describe bacteria or yeast in the urine. Very ill patients
may be referred to as having urosepsis.

2. * Classification
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UTI is a spectrum ranging from those without symptoms to those with symptoms.
The following clinical categories are used generally to describe UTI.
Asymptomatic bacteriuria,
cystitis and
pyelonephritis.

3. *
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UTI in Pregnancy
Kampala international university-
western campus
Mubende Hosp
28th/3/2020
*MWBAZA VICTOR™
MBchB

4. *Asymptomatic bacteriuria (ASB)
refers to 2 consecutive urine cultures growing more than 100,000 colony-forming
units (CFU) of a bacterial species in a patient lacking symptoms of a UTI.

5. *Cont..
Untreated asymptomatic bacteriuria may →pyelonephritis in 50% of cases and
acute cystitis in 30% of cases and IUGR and LBW infants.
Treatment as outpatient. The choice of antibiotics should address the most
common infecting organisms and should also be safe for the mother and the
fetus.

6. *Cystitis
Cystitis occurs in approximately 1% of pregnant patients. It is distinguished from
asymptomatic bacteriuria by the presence of symptoms.
e.g dysuria, urgency, hematuria, suprapubic discomfort or pain and frequency in
afebrile patients with no evidence of systemic illness

7. *Cont..
On Examination may reveal suprapubic tenderness. However, these clinical features
during pregnancy may have other causes other than UTI.
Urine dipstick usually shows leukocyte esterase, nitrite, hematuria, and proteinuria.
A urine culture may be positive for the incriminated organism.
Acute cystitis is complicated by upper urinary tract disease (ie, pyelonephritis)
15-50% of the time.

8. *PYELONEPHRITIS
Diagnosis is made by the presence of significant bacteriuria (100
organisms per mL of urine) accompanied by systemic symptoms
such as fever, flank pain, chills nausea and vomiting
Symptoms of lower tract infection (i.e. dysuria and frequency) may
or may not be present.

9. *Cont..
Occurs in 2% of pregnant women; up to 23% of these women have a recurrence
during the same pregnancy.
Blood cultures are positive in up to 20 percent of women who have this infection.
With the exceptions of white cell casts on urinalysis, and bacteremia and flank pain
on physical examination, none of the physical or laboratory findings are specific for
pyelonephritis.

10. *Cont..
Pregnant women with pyelonephritis should be hospitalized.
Early aggressive treatment with i.v antibiotics and i.v fluids.
Parenteral treatment should continue until the patient becomes afebrile.
Most patients respond to hydration and prompt antibiotic treatment within 24-48
hours. The total duration of treatment for acute pyelonephritis is at least two weeks.

11. *Etiology
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The most common pathogens include
Escherichia coli (causes 70-95%
),
enterococci,
Pseudomonas aeruginosa,
Klebsiella pneumonia,
Staphylococcus saprophyticus.
The commonest urinary pathogens are Escherichia coli, Klebsiella
pneumoniae, and Proteus mirabilis. As many as 90 percent of
uncomplicated cystitis episodes are caused by Escherichia coli.

12. *Cont..
90 percent of uncomplicated cystitis episodes are caused byEscherichia coli .
Uropathogenic E. coli have special characteristics causing urovirulence
Less common organisms that may cause UTI include, Gardenerella vaginalis and
Ureaplasma urealyticum.

13. *Risk factors in pregnancy
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Structural abnormalities:
Expanding uterus compresses the Bladder and ureters resulting in stasis.
Short vesico-uretheral distance
Hormonal changes: General renal system dilatation in response to progesterone
smooth muscle relaxing effect, may result in urine stasis.

14. *Cont..
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Additionally, glycosuria and aminoaciduria during pregnancy provide an excellent
culture medium in areas of urinary stasis.
Impaired host responses: Immunosuppressive effect of pregnancy.
Catheters: In-dwelling catheter
Metabolic abnormalities: Gestational diabetes mellitus.
Nosocomial in origin

15. *Pathophysiology
In general, 3 main mechanisms are responsible for UTIs, including
(1) Colonization with ascending spread,
(2) Hematogenous spread, and
(3) Periurogenital spread of infection. Specific organism characteristics,
defects in host defenses.

16. *Cont..
Uropathogenic bacteria, derived from a subset of fecal flora, have traits that enable
adherence, growth, and resistance of host defenses, resulting in colonization and
infection of the urinary tract.
E. coli virulence in the urinary tract include 1 fimbriae bind to mannose-containing
structures, capsular polysaccharides, hemolysins, cytotoxic necrotizing factor (CNF)
protein, and aerobactins.
Swarming capability of Proteus mirabilis.

17. *CLINICAL FEATURES
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90% Non-specific
Hx: Frequency, dysuria, urgency, hesitancy, polyuria, burning and incomplete voids.
Constitutional symptoms, such as fever, nausea, and anorexia, are rare or mild.
Acute pyelonephritis: The classic triad offever, lower back or flank pain, and
nausea and/or vomiting.
Physical exam: Suprapubic tenderness to palpation, increased temperature, Unilateral or
bilateral costovertebral angle tenderness may be present.

18. *Diagnosis
1.
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Urinalysis: Urine specimens may be obtained by suprapubic
aspiration, catheterization, or midstream clean catch.
Dipstick and microscopic analysis showing pyuria and/or positive
nitrite/leukocyte esterase tests can be used as presumptive
evidence of UTI.
Urine culture remains the criterion standard for the diagnosis of
UTI.
2. CBC and Blood Culture.
3. Imaging: USG
4. LFTs, BUN/Creatinine, Serum electrolytes.

19. *Management of UTI in pregnancy
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Goals
Elimination of infection and prevention of urosepsis
Prevention of recurrence and long-term complications including
hypertension, renal scarring, PROM, Premature labor)
Relief of acute symptoms (eg, fever, dysuria, frequency, pain)

20. *Treatment
ANTIBIOTIC THERAPY: Broad spectrum antibiotics are used ( 3rd generation
cephalosporins, Penicillins, Macrolides, nitrofurantoin.
Mild: oral antibiotics
Severe: IV antibiotics

21. *Complications of UTI in Pregnancy
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PROM
Premature labor.