Urinary system infections are the most common infections during pregnancy. Asymptomatic bacteriuria can be classified into cystitis and pyelonephritis. The most common (75-90%) pathogenic agent responsible for urinary tract infections is Escherichia coli, other pathogens are Klebsiella, Proteus, Enterobacter, Staphylococcus saprophyticus and group B Streptococcus. Asymptomatic bacteriuria; In non-symptomatic women, two urine cultures taken at least 24 hours apart have ≥ 105 cfu/ml bacteria and pyuria.
Acute cystitis; It is a symptomatic infection of the bladder manifested by frequent urination, dysuria, urge incontinence and foul-smelling urine without clinical evidence of systemic disease. Acute pyelonephritis is renal parenchymal inflammation; Symptoms include side and back pain, costovertebral angle tenderness, fever (>38ºC), nausea, vomiting and cystitis. It is a serious and febrile disease that requires urgent and aggressive treatment and is the most common cause of hospitalization during pregnancy.
Maternal and neonatal morbidity and mortality increase in untreated asymptomatic bacteriuria cases. While pyelonephritis may develop in 30-40% of untreated cases, the frequency of pyelonephritis is about 1% in cases where bacteriuria is not detected in early pregnancy or in treated asymptomatic bacteriuria cases.
With the eradication of asymptomatic bacteriuria, the risk of pyelonephritis decreases by 70-80%. 12-16. Screening for asymptomatic bacteriuria is recommended between weeks of pregnancy. Cases with asymptomatic bacteriuria must be treated. Nitrofurantoin, β lactam antibiotics, cephalosporins and phosphomycin trometamol can be used safely. There is a 30% failure rate in the treatment of asymptomatic bacteriuria; The culture should be repeated one week after the completion of treatment, and urine culture should be followed at 4-6 week intervals throughout pregnancy. In cases of recurrent asymptomatic bacteriuria, daily Nitrofurantoin (50-100 mg before bedtime) and close follow-up are recommended throughout pregnancy. . Cases of acute pyelonephritis during pregnancy should be hospitalized, the function of all systems should be evaluated, and intravenous (iv) antibiotics and supportive treatment should be started. After a fever-free period of 24-48 hours, 10-14 days of oral antibiotic treatment should be continued.
One week after completion of treatment Then the culture should be repeated and urine culture should be followed up every 4-6 weeks throughout pregnancy. Prophylaxis is not recommended in cases of recurrent cystitis and pyelonephritis, only close follow-up is recommended.
Introduction: Urinary system infections are the most common infections during pregnancy (1, 2). It starts in the 6th week of pregnancy and continues on the 22-24th week. The risk of urinary stasis and vesicoureteral reflux increases with hormonal and mechanical changes that become most evident between weeks. Additionally, with the addition of glycosuria and aminoacituria, urinary stasis becomes a good medium for bacteria. In addition, the frequency of urinary tract infections increases during pregnancy due to the short urethra and difficulties in maintaining genital hygiene (2,3). The most common (75-90%) pathogenic agent responsible for urinary tract infections is Escherichia coli, other pathogens are Klebsiella, Proteus, Enterobacter, Staphylococcus saprophyticus and group B Streptococcus (2, 4, 5).
It is known that most cases of untreated symptomatic or asymptomatic bacteriuria during pregnancy are complicated by preterm birth, low birth weight babies, and neonatal morbidity and mortality (2,6). Nitrofurantoin, β lactam antibiotics, cephalosporins and phosphomycin trometamol can be used safely in the treatment of urinary tract infections during pregnancy. The use of sulfonamides in the last trimester and fluoroquinolones during pregnancy should be avoided (7).
With this presentation, it is aimed to discuss asymptomatic bacteriuria, lower (cystitis) and upper (pyelonephritis) urinary tract infections and their current management.
Asymptomatic Bacteriuria: Asymptomatic bacteriuria; The presence of ≥ 105 cfu/ml bacteria and pyuria in two urine cultures taken at least 24 hours apart in non-symptomatic women. The frequency of asymptomatic bacteriuria is 5-10% in pregnant women; The risk of recurrence and complications during pregnancy is much higher (8). In studies conducted in our country, the frequency of asymptomatic bacteriuria was found to be 7.8-10.6% (9-12). The frequency of asymptomatic bacteriuria increases parallelly throughout pregnancy. Low socioeconomic status, history of recurrent symptomatic or asymptomatic bacteriuria, untreated vesicoureteral reflux, renal calculi, neurogenic bladder, pregestational diabetes and sickle cell anemia increase the frequency of asymptomatic bacteriuria. are other risk factors (4,13-15).
It has been reported by many clinics that untreated asymptomatic bacteriuria cases are associated with premature labor and small birth weight babies. In addition, while pyelonephritis may develop in 30-40% of untreated asymptomatic bacteriuria cases, the frequency of pyelonephritis is about 1% in cases where bacteriuria is not detected in early pregnancy or in treated asymptomatic bacteriuria cases. With the eradication of asymptomatic bacteriuria, the risk of pyelonephritis decreases by 70-80% (16,17). Therefore, 12-16. Screening for asymptomatic bacteriuria is recommended between weeks of pregnancy (6,17-20).
Urine culture is the gold standard in the diagnosis of asymptomatic bacteriuria. It is very important to collect urine appropriately sterile. In particular, cleaning should be done from front to back with antiseptic solution and water. Midstream urine should be collected after the first urine is expelled. For the definition of asymptomatic bacteriuria, the same bacteria must grow ≥105 cfu/ml in two consecutive cultures (≥24 hours apart). Another definition is the growth of a single isolated bacterial species ≥102 cfu/ml in the urine sample obtained by catheter. Proper sample collection and processing is important to avoid false positivity. The growth of more than one bacterial species in the urine culture and the presence of Lactobacillus or Propionibacterium should suggest contamination (2,5).
Other tests used in the screening of asymptomatic bacteriuria; reagent strip test (presence of nitrite, protein, erythrocyte, leukocyte esterase indicates pyuria), enzymatic screening test (catalase activity), urinary interleukin (IL-8), microscopic urinary analysis (≥1 leukocyte in each field in 40 x magnification microscope examination of uncentrifuged urine or ≥10 leukocytes/mm3 in the tomo slide count or >5 leukocytes in each field in the 40x magnification microscope examination of centrifuged urine indicates pyuria) and gram staining (1 bacteria in the 40x magnification microscope examination indicates that ≥105 cfu/ml bacteria will grow in the culture). indicator) tests can be used. However, in many studies, the sensitivity, specificity and positive predictive values of these tests in the screening of asymptomatic bacteriuria are very low compared to culture screening. It has been reported that k (21-24). In their study, Bachman et al. investigated the diagnostic values of rapid screening tests in screening for asymptomatic bacteriuria. They reported the sensitivity of the urinary dipstick method as 50%, the specificity as 96.9%, the sensitivity of the presence of leukocytes in microscopic urine analysis as 25%, the specificity as 99%, and the sensitivity of the gram stain method as 91.7% and specificity as 89.2% (21). The sensitivities of urinary interleukin-8 (22) and rapid enzymatic screening tests (23) used in the screening of asymptomatic bacteriuria have been reported as 70%; It causes 30% of asymptomatic bacteriuria cases to be misjudged.
It is known that treatment of asymptomatic bacteriuria reduces maternal and fetal complications. As a result of Smaill and Vazquez's meta-analysis study including 14 studies; Treatment of asymptomatic bacteriuria reduced the persistence of asymptomatic bacteriuria (risk ratio (RR) 0.25, 95% confidence interval (CI) 0.14 - 0.48), the incidence of pyelonephritis (RR 0.23, 95% CI 0.13-0.41) and the incidence of low birth weight babies (RR 0.66, They reported that it decreased (95% CI 0.49-0.89). However, they could not detect any difference in the frequency of preterm birth (17).
No significant differences were found between the effectiveness and safety of antibiotics used in the treatment of asymptomatic bacteriuria during pregnancy. It should be known that the use of nitrofurantoin in pregnant women with glucoseephosphate dehydrogenase deficiency may theoretically cause hemolytic anemia in the newborn, and its use close to birth should be avoided. Again, sulfonamides can be used in the second trimester of pregnancy, but the high rate of resistance to sulfonamides and their lack of superiority over other antibiotics restrict their use. Additionally, the use of quinolones during pregnancy is contraindicated.
If the repeated culture is positive (≥105 cfu/ml) and the same bacteria, a different antibiotic regimen should be used. In addition, if the previously used treatment regimen is short-term (3 days), it must be changed to a long-term regimen (7 days). If the repeated culture is positive and different bacteria, appropriate antibiotics should be used. Monitoring with monthly cultures for persistent and recurrent bacteriuria throughout pregnancy
Acute Cystitis: Acute cystitis; It is a symptomatic infection of the bladder that manifests itself with frequent urination, dysuria, urge incontinence and foul-smelling urine without clinical evidence of systemic disease (2). The frequency of acute cystitis during pregnancy has been reported as 1.3-2.3% (26, 27). No correlation has been found between acute cystitis during pregnancy and low birth weight babies, preterm birth and pyelonephritis (2, 28). As a possible reason for this; Since the cases are symptomatic, early diagnosis and treatment are considered.
In the diagnosis of acute cystitis, the presence of symptoms and urine culture are the gold standards. Urine microscopy and reagent strip test also help in rapid diagnosis. In clinical practice, urine culture, microscopy and reagent strip tests are used together in patients with symptoms of acute cystitis. If microscopy (leukocytes seen) and or dipstick test are positive (nitrite and leukocyte esterase), acute cystitis is likely and empirical treatment can be started (2). No significant differences were found between the effectiveness of antibiotics used in the treatment of acute cystitis during pregnancy, the need for antibiotic changes, recurrent infection rates, the frequency of preterm birth, the need for neonatal intensive care, and their safety (28). The regimens recommended for the treatment of acute cystitis during pregnancy and the regimens for the treatment of asymptomatic bacteriuria are the same and are given in table-1.
Urinary culture control should be performed one week after completing antibiotic treatment in the follow-up of acute cystitis. In addition, monthly culture follow-up is recommended throughout pregnancy in terms of persistent and recurrent bacteriuria. When persistent or recurrent bacteriuria is detected; It should be evaluated in terms of diabetes and urinary system anomalies and antibiotic treatment should be re-planned (2, 6, 29). Although there are clinics and authors recommending suppression therapy (nitrofurantoin 50-100 mg or cephalexin 250-500 mg postcoital or before bedtime) in cases of recurrent cystitis, currently suppression therapy (daily nitrofurantoin) and close follow-up (regular culture follow-up and antibiotic treatment in case of culture positivity) are recommended. No significant difference was detected between the rates of recurrent infection and preterm birth between the cases and the cases only followed closely (6). However, Pfau and Sacks reported a history of recurrent cystitis before pregnancy.
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