urinary tract infection in pregnancy (2023)

continuing education activity

Urinary tract infections (UTIs) are common in pregnant women. Pyelonephritis is the most common serious condition in pregnancy and can present in a similar way and even be the result of inadequate treatment of urinary tract infections. Therefore, it is crucial that clinicians be able to differentiate between normal and abnormal findings of the urinary tract and kidneys, assess for abnormalities, and treat disease. Fortunately, UTIs in pregnancy are usually easy to treat and respond well to treatment. This activity reviews the evaluation and management of UTIs in pregnancy and highlights the role of interprofessional team members in working together to provide well-coordinated care and improve patient outcomes.

Goals.

• Identify the etiology of urinary tract infections in pregnancy.

• Explain how urinary tract infections are diagnosed in pregnant patients.

• Outline the treatment options available for urinary tract infections in pregnant patients.

• Review of interprofessional team strategies to improve care and outcomes in pregnant patients with urinary tract infections.

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introduction

Urinary tract infections (UTIs) are common in pregnant women. Pyelonephritis is the most common serious disease in pregnancy. Therefore, it is crucial that obstetricians are aware of normal urinary tract findings, evaluation for abnormalities, and treatment of disease. Fortunately, UTIs during pregnancy are easier to treat with excellent results. Rarely, pregnancies complicated by pyelonephritis result in significant maternal and fetal morbidity.

Changes in the urinary tract and immunological changes during pregnancy predispose women to urinary tract infections. Physiologic changes in the urinary tract include dilatation of the ureter and calyces of the kidneys; This is due to progesterone-induced smooth muscle relaxation and ureteral compression by the gravid uterus. Ureteral dilatation may be marked. Decreased bladder capacity often leads to frequent urination. Vesicoureteral reflux can occur. These changes increase the risk of urinary tract infections.

etiology

During pregnancy, changes in the urinary tract predispose women to infections. Dilation of the ureters is seen due to compression of the ureters by the gravid uterus. The hormonal effects of progesterone can also cause smooth muscle relaxation, leading to urinary dilation and stasis and increased vesicoureteral reflux. The organisms that cause UTIs in pregnancy are the same uropathogens seen in non-pregnant women. As in non-pregnant patients, these uropathogens have cell surface proteins that increase bacterial adhesion, resulting in increased virulence. Urinary catheterization, which is often done during labor and delivery, can introduce bacteria that cause urinary tract infections. In the postpartum period, changes in bladder sensation and bladder distension may predispose to UTIs.

Pregnancy is a state of relative immunodeficiency. This immunodeficiency may be another reason for the increased frequency of urinary tract infections seen in pregnancy.

Epidemiology

The most important factor predisposing women to UTIs in pregnancy is asymptomatic bacteriuria (ASB). ASB is defined as more than 100,000 organisms/mL in a clean urinalysis from an asymptomatic patient. If asymptomatic bacteriuria is not treated during pregnancy, the subsequent UTI rate is about 25%.[1]Due to the high incidence and potential severity of pyelonephritis, it is recommended that all pregnant women be screened for ASB at their first prenatal visit. This is usually done with a clean urine culture. Treatment of ASB reduces the clinical infection rate from 3% to 4%.

The rate of asymptomatic bacteriuria in nonpregnant women is 5% to 6%, which compares with estimated rates in pregnancy of 2% to 7%. ASB is seen more frequently in multiparous women and women of low socioeconomic status. Women with sickle cell signs also have a higher incidence of ASB.[1]

UTIs are a common cause of serious infections in pregnant women. In one study, 3.5% of prenatal admissions were due to urinary tract infections.[2]Pyelonephritis is the most common cause of septic shock in pregnant women. Risk factors for urinary tract infections in pregnancy include low socioeconomic status, young age, and nulliparity. As with ASB, some patients may be predisposed to infection and report a history of ASB, cystitis, or pyelonephritis. Pyelonephritis is more common on the right side, but can be bilateral in up to 25% of cases.

pathophysiology

The organisms that cause UTIs in pregnancy are the same uropathogens that commonly cause UTIs in nonpregnant patients.Escherichia coliIt is the most frequently isolated organism. A retrospective analysis of 18 years foundE. colibe the causative agent in 82.5% of cases of pyelonephritis in pregnant women.[3]Other bacteria that may be seen includeKlebsiella pneumoniae, Staphylococcus, Streptococcus, Proteus,mithe enterococcusSpecies.

history and body

Patients with asymptomatic bacteriuria have no symptoms; Therefore, it is important to check for the disease. These patients may have a history of frequent urinary tract infections or may have had ASB in a previous pregnancy.

Cystitis presents the same symptoms that are seen in non-pregnant people. Symptoms may include pain or burning when urinating (dysuria), frequent urination, or the urge to urinate. Suprapubic pain and tenderness may be noted.

Also, patients with pyelonephritis have symptoms that have been observed in non-pregnant patients with the same disease. Symptoms can include flank pain, fever, and chills. Nonspecific symptoms such as malaise, anorexia, nausea, and vomiting may occur, so the differential diagnosis at initial presentation is usually broad. The differential diagnosis includes acute intra-abdominal processes such as appendicitis, cholecystitis, and pancreatitis, as well as pregnancy complications including preterm labor and placental abruption. Patients may report contractions or contractions may be observed with uterine monitoring. This uterine activity is usually due to smooth muscle irritability caused by infection. Patients should be evaluated, and if no cervical dilation is noted, treatment for preterm labor is usually not required. However, patients should be closely monitored as preterm labor may develop.

Signs and symptoms of sepsis may be present. These include tachycardia and hypotension. These patients require immediate evaluation and intervention.

A complete physical examination should be performed with particular attention to vital signs and examination of the heart and lungs. An abdominal examination may show tenderness, and costovertebral tenderness can usually be detected. A urogenital examination (UG) should be performed to assess for cervical infection and assess for cervical dilation on admission. Although complications of pregnancy are not an initial concern, it is still useful to assess for abnormalities in labor or other abnormalities during the hospital stay.

Assessment

Evaluation includes a urinalysis and a clean urine culture. There are some considerations worth mentioning when collecting urine samples during pregnancy. Well-hydrated patients may excrete dilute urine, which makes some parameters evaluated less precise. Hematuria may be seen as a result of contamination, particularly when collecting samples from labor or postpartum patients. Due to reduced protein reabsorption, small amounts of protein can normally be excreted. Contamination, such as that which can occur with mucous secretions, can also contribute to the presence of proteinaceous material in the urine of pregnant women.

Laboratory tests should include a complete blood count (CBC), electrolytes, and serum creatine. Where appropriate, custom studies should be included to rule out other causes of the patient's symptoms, e.g. B. amylase and lipase when pancreatitis is considered as a diagnosis. If there is concern about sepsis, lactic acid and blood cultures should be taken. All cultures should be collected as soon as possible and before starting antibiotic therapy.

If the fetus is viable, fetal heart rate and contractions should be monitored. Cervical cultures and GBS should be considered on admission if pregnancy-related complications occur. Rarely, renal ultrasonography may be indicated to evaluate for possible renal abscess.

Treatment / Management

ASB and acute cystitis are treated with antibiotic therapy. The choice of antibiotic can be tailored based on the susceptibility of the organism when it becomes available from urine culture results. One-day courses of antibiotics are not recommended during pregnancy, although 3-day courses are effective.[4]Commonly used antibiotics are amoxicillin, ampicillin, cephalosporins, nitrofurantoin, and trimethoprim-sulfamethoxazole. Fluoroquinolones are not recommended as first-line treatment in pregnancy due to conflicting studies of teratogenicity. Short courses are unlikely to be harmful to the fetus, so it makes sense to use this class of drugs for recurrent or resistant infections.

Evidence has recently emerged suggesting a link between the use of sulfa derivatives and nitrofurantoin and birth defects when these drugs are prescribed in the first trimester. These studies had limitations; However, it is currently recommended not to use these drugs in the first trimester if alternatives are available.[5]Because the potential consequences of an untreated UTI during pregnancy are significant, it makes sense to use these medications when necessary, as the benefits far outweigh the risks of use. There is extra caution with these two classes of antibiotics. Patients with G6P deficiency should not be prescribed sulfa derivatives or nitrofurantoin, as these drugs can induce hemolysis. At the end of the third trimester, trimethoprim-sulfamethoxazole should be avoided due to the potential risk of the baby developing kernicterus after birth.

If group Bstreptococci(GBS) on urine cultures, patients should receive intravenous (IV) antibiotic therapy at the time of delivery in addition to treatment indicated for ASB or UTI. This is to prevent the development of early-stage GBS sepsis, which can occur in babies born to women colonized with GBS.

Pyelonephritis in pregnancy is a serious condition that often requires hospitalization. Once evaluation is complete, treatment consists primarily of targeted antibiotic therapy and intravenous fluids to maintain adequate urinary output. Fever should be treated with a cooling blanket and paracetamol if necessary. Second- or third-generation cephalosporins are often used for initial treatment. Alternatives are ampicillin and gentamicin or other broad-spectrum antibiotics. Patients should be closely monitored for the development of worsening sepsis.

differential diagnosis

The differential diagnosis includes acute intra-abdominal disorders, such as appendicitis, pancreatitis, or cholecystitis, as well as pregnancy-related complications, such as preterm labor, chorioamnionitis, or placental abruption.

complications

Patients with pyelonephritis are at risk of several major complications.

Sepsis may worsen, resulting in hypotension, tachycardia, and decreased urine output. Admission to the intensive care unit may be required.

Pulmonary complications are not uncommon and occur in up to 10% of pregnant patients treated for pyelonephritis.[4]This is due to endotoxin-mediated alveolar damage and can manifest as pulmonary edema or acute respiratory distress syndrome (ARDS). Urine output and oxygen status must be closely monitored, and patients may require respiratory support in the intensive care unit.

The release of endotoxins can lead to anemia, which usually resolves spontaneously after treatment. This is the most common complication of pyelonephritis, occurring in up to 25% of patients.[3]

Endotoxin release can also cause uterine contractions and patients should be monitored for preterm labor; Patients should receive treatment for preterm labor when indicated. Caution should be exercised when using tocolytic therapy because of the increased risk of pulmonary edema in urinary tract infections.

A small number of patients may have a persistent infection. In these cases, urinary obstruction or renal abscess should be considered. The choice of antibiotic should be reassessed and the culture results reviewed.

Warning and information for the patient

A urine culture should be taken 2 to 4 weeks after stopping treatment to ensure that reinfection has not occurred.

Suppressive antibiotic therapy, usually once daily with nitrofurantoin, is often recommended, particularly in cases where patients have had a previous urinary tract infection. This usually continues throughout the pregnancy and early postpartum period.

Improve the results of the health team

Interprofessional collaboration is essential in the treatment of these patients. When antibiotics are given, patients may initially worsen due to endotoxin release, but most patients improve within 72 hours. Long-term complications, such as kidney damage, are rare.

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references

1.

Gilstrap LC, Ramin SM. Urinary tract infections during pregnancy.Obstetricia Gynecol Clin North Am.September 2001;28(3):581-91.[PubMed: 11512502]

2.

Gazmararian JA, Petersen R, Jamieson DJ, Schild L, Adams MM, Deshpande AD, Franks AL. Hospitalizations during pregnancy among those participating in managed care.Obstetrics Gynec.July 2002;100(1):94-100.[PubMed: 12100809]

3.

Wing DA, Fassett MJ, Getahun D. Acute pyelonephritis in pregnancy: an 18-year retrospective analysis.Soy J Obstet Gynecol.2014 March;210(3):219.e1-6.[PubMed: 24100227]

4.

Sheffield JS, Cunningham FG. urinary tract infection in women.Obstetrics Gynec.November 2005;106(5 point 1): 1085-92.[PubMed: 16260529]

5.

Committee Opinion No. 717: Sulfonamides, Nitrofurantoin, and the Risk of Birth Defects.Obstetrics Gynec.September 2017;130(3):e150-e152.[PubMed: 28832488]

(Video) UTI in Pregnancy - CRASH! Medical Review Series