1
Forth stage
Obstetric
Lec-5
.د
امنة
1/1/2016
URINARY TRACT DISORDER IN PREGNANCY
Introduction
Urinary tract infections (UTIs) are the most common bacterial infection during pregnancy.
They are associated with risk to the fetus & the mother.
Physiological adaptation to pregnancy
1-urinary frequency is a common pregnancy related complaint, related to increase total
urinary output, due to higher fluid intake, plasma volume expansion & increase in renal
blood flow & GFR rather than changes in bladder function.
2-increases in urinary incontinence.
3-pregnancy related hormonal & mechanical factors induce changes in the renal collecting
system (dilatation) that lead to urinary stasis which is crucial to the pathophysiology of UTI
in pregnancy.
Pathogenesis of infection
*The female urethra measures only 3-4 cm in length. Its proximity to the vagina & rectum
facilitates colonization of urine from the normal flora of the gastrointestinal tract & vagina.
*Also lower renal thresholds for excretion of glucose& amino acid during pregnancy
provide an excellent media for proliferation of microorganisms. In addition,
*The dilated urinary collecting system predisposes the pregnant woman to the
development of infection from
a symptomatic bacteriuria.
Screening for UTI should be done at 16 wk of gestation.
Classifications of UTIs in pregnancy
1-Asymptomatic bacteriuria
2-Cystitis
3-Pyelonephritis
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Risk factors for UTI in pregnancy
-previous history of UTI especially before 20wk of gestation.
-multiparity
-lower socioeconomic status
-DM
-anatomical abnormalities
-advanced maternal age
-presence of hemoglobin S
Causative organisms
Escherichia coli (E.coli) in 90% of cases of asymptomatic bacteriuria, cystitis &
pyelonephritis.
Klebsiella, streptococcus, staphylococcus, proteus, pseudomonus & others.
1-Asymptomatic bacteriuria
It's the presence of 100 000 organisms/ ml of the same species in two cultured fresh
midstream specimens of urine in a woman without symptoms.
It occurs in 2-7% of pregnant women. If left un-treated, 30% of them will develop
symptomatic infections.
Complications
1-symptomatic infections as cystitis & pyelonephritis.
2-anaemia
3-hypertension.
4-lUGR.
5-preterm delivery.
Treatment
Amoxicillin 500 mg/8hr or Cephalosporin as cefixime 500 mg/6hr for 10 days or
Nitrofurantoin 100 mg/6 hr.
2-Cystitis
It occurs in 0.3-1.3% of pregnant women (rare in pregnancy). Unlike Asymptomatic
bacteriuria, there is no evidence to suggest an increase in pyelonephritis, low birth weight
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infants or preterm labour among patients with cystitis. Bacteria are confined to the lower
urinary tract in these patients.
Clinical features & Diagnosis
Acute cystitis should be considered in any pregnant with symptoms of frequency, urgency,
dysuria, hematuria or suprapubic pain in the absence of fever & flank pain.
GUE (presence of pyuria) & urine culture for the diagnosis.
Treatment
1-hydration to wash the bacteria.
2-antibiotics, obtain a urine culture in patient with signs & symptoms suggestive of cystitis
& start antibiotic therapy, then adjust the treatment depend on final culture results & the
patient's response to therapy. The same microorganisms associated with asymptomatic
bacteriuria are responsible for cystitis & the same antibiotics are used to treat it. Types of
antibiotics given; Ampicillin, Amoxicillin, Augmentin, Nitrofurantoin.
3-Pyelonephritis
It's inflammation of the renal pelvis & parenchyma. It's most serious complication in
pregnancy; it may cause renal dysfunction & even renal failure.
It occurs in 1-2% of all pregnancies.
Predisposing factors during pregnancy
-urine stasis during pregnancy due to; compression of the ureter by the gravid uterus
against the pelvic brim particularly on the right side. So infection is more common on the
right side. Also relaxation of the ureter by progesterone effect.
-increase urinary excretion of glucose & amino acid favours the growth of bacteria.
Clinical features
It may be asymptomatic or patient present with septicemia & shock.
Symptoms started usually after 16 wks in form of;
-malaise
-anorexia
-nausea & vomiting
-rigor
-dysuria
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-urgency, frequency of micturition.
-flank pain commonly on the right side.
Signs
-fever reaching 40 C°.
-rapid pulse
-tenderness in one or both renal angles.
Differential diagnosis
1-causes of acute abdomen as appendicitis, abruption placenta (concealed type) &
complications of pelvic tumour (fibroid), ectopic pregnancy.
2-labour
3-chorioamnionitis
Investigations
1-urine analysis (midstream)..... Pus cells, bacteruria, proteinurea, RBC cast may be present.
2-urine culture & sensitivity to isolate mo. (mostly E.coli).
3-blood picture...... anemia, leukocytosis, thrombocytopenia.
4-RFT.....GFR, serum creatinine.
Note. Routine imaging studies are not indicated in the evaluation of pregnancy related UTI.
Renal US or IV pyelography may be helpful in patients with recurrent UTI or symptoms
suggestive nephrolithiasis.
Complications
1-chronicity due to recurrent infections. In these cases, plain X-ray & IV pyelography should
be done after delivery to exclude urinary stones.
2-hypertension & renal failure (in chronic case).
3-pulmonary oedema & adult RDS due to dehydration.
4-effect on fetus; abortion, preterm labour, prenatal mortality & morbidity.
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Treatment
Should be more aggressive;
1-admition to hospital "some patient can be managed as outpatients" & bed rest
2-light diet & rehydration. IV fluid may be needed if there is vomiting.
3-analgesics & antipyretics.
4-alkalies as K citrate to inhibit the growth of E.coli.
5-antibiotics as ampicillin 500 mg/ 6hr or nitrofurantoin 100 mg/ 6hr or cephalosporins 500
mg/6hr until the result of culture & sensitivity. The treatment is continued for 7-10 days.
We can start IV antibiotics then shift to oral antibiotics after 24-48hr when she is afebrile.
6-repeat culture after 2 wk.s