Renal infection and pregnancy outcome

The association between bacteriuria and adverse pregnancy outcomes: a systematic review and meta-analysis of observational studies

BACKGROUND

Antibiotics for bacteriuria and urinary tract infection are commonly prescribed during pregnancy to avoid adverse pregnancy outcomes. The aim of this study was to evaluate the association between significant bacteriuria in pregnancy and any of the four pregnancy outcomes: preterm delivery; low birth weight; small for gestational age; and preterm labour.

METHODS

Systematic review with meta-analysis of observational studies. We searched PubMed, EMBASE, the Cochrane CENTRAL library, and Web of Science for observational studies published before 1 March 2022. The risk of bias was assessed using the Newcastle-Ottawa scale. Study identification, data extraction and risk-of-bias assessment was performed by two independent authors. We combined the included studies in meta-analyses and expressed results as ORs with 95% CIs (Prospero CRD42016053485).

RESULTS

We identified 58 studies involving 421 657 women. The quality of the studies was mainly poor or fair. The pooled, unadjusted OR for the association between any significant bacteriuria and: (i) preterm delivery was 1.62 (95% CI: 1.30-2.01; 27 studies; I2 = 61%); (ii) low birth weight was 1.50 (95% CI: 1.30-1.72; 47 studies; I2 = 74%); (iii) preterm labour was 2.29 (95% CI: 1.53-3.43; 3 studies; I2 = 0%); and (iv) small for gestational age was 1.33 (95% CI: 0.88-2.02; 7 studies; I2 = 54%). Four studies provided an adjusted OR, but were too diverse to combine in meta-analysis.

CONCLUSIONS

This systematic review identified an association between significant bacteriuria in pregnancy and the three complications: preterm delivery; low birth weight; and preterm labour. However, the quality of the available evidence is insufficient to conclude whether this association is merely due to confounding factors. There is a lack of high-quality evidence to support active identification and treatment of bacteriuria in pregnancy.

"Urinary tract dilatation and vesicoureteral reflux - Adult outcomes, who should be followed, and how to follow them"

Long-term adult outcomes of children diagnosed with urinary tract dilatation (UTD) and vesicoureteral reflux (VUR) are not clearly documented in the literature. Likewise, follow-up protocols for these patients as they transition through adolescence and into adulthood vary with institution and cultures. Several studies have shown that individuals diagnosed with VUR in childhood are at higher risk of urinary tract infection (UTI) throughout their lives, even in the setting of prior VUR resolution or surgical correction. This is particularly relevant in patients with renal scarring, who are at higher risk of UTIs, hypertension and renal function deterioration in pregnancy. The risk of adverse maternal and fetal outcomes in pregnancy are higher for women with significant chronic kidney disease (CKD). Patients who underwent endoscopic injection or reimplantation should be counselled on the long-term particular risks associated with each intervention, including calcification of ureteric injection mounds, and the potential challenges of future endoscopic procedures following reimplantation. Although there is no evidence for the direct correlation between conservatively managed UTD in childhood, and symptomatic UTD diagnosed in adulthood, all patients should be aware of the long-term risks of persistent upper tract dilatation. Lastly, bladder-bowel dysfunction (BBD) management in adolescence can be more challenging and may contribute to symptomatic recurrence in this age group.

Urology mythbusters: do we need to surgically correct vesicoureteral reflux in older girls to prevent problems in future pregnancy? (revision 1)

In this edition of Mythbusters we critically examine the premise that, because women with history of vesicoureteric reflux (VUR) are at higher risk of urinary tract infection (UTI) and other morbidity during pregnancy, persistent VUR in older girls should be considered an indication for surgical correction. The literature is very limited in that there are essentially no methodologically robust comparisons of pregnancy outcomes among women whose childhood VUR was or was not surgically repaired. Most of the case series and cohorts find relatively high incidence of UTI and pyelonephritis among pregnant women with a history of VUR, but there is very little to suggest that persistent VUR is itself a risk factor for infection during pregnancy. Indeed, some studies suggest that UTI risk is actually higher among women who previously underwent anti-reflux surgery compared to those who did not, although these data are compromised by significant selection bias. In contrast, there is relatively strong evidence that maternal and fetal morbidity is higher when the mother is known to have renal scarring; such women probably merit close surveillance during pregnancy for infection, hypertension and pre-eclampsia, and other problems. Overall, current evidence is insufficient to support routine anti-reflux surgery in girls with the sole purpose of decreasing complications during future pregnancy, particularly for girls with lower-grades of VUR and no renal scarring. The verdict for this urolegend: it contains a a "teeny, tiny nugget of truth."

The Uriscreen Test to Detect Significant A symptomatic Bacteriuria During Pregnancy

BACKGROUND

Asymptomatic bacteriuria (ASB) occurs in 2-11% of pregnancies and it is a clear predisposition to the development of acute pyelonephritis, which, in turn, poses risk to mother and fetus. Treatment of bacteriuria during pregnancy reduces the incidence of pyelonephritis. Therefore, it is recommended to screen for ASB at the first prenatal visit. The gold standard for detection of bacteriuria during pregnancy is urine culture, but this test is expensive, time-consuming, and labor-intensive.

OBJECTIVE

To determine the reliability of an enzymatic urine screening test (Uriscreen; Savyon Diagnostics, Ashdod, Israel) for detecting ASB in pregnancy.

METHODS

Catheterized urine samples were collected from 150 women who had routine prenatal screening for ASB. Patients with urinary symptoms, active vaginal bleeding, or who were previously on antibiotics therapy were excluded from the study. Sensitivity, specificity, and the positive and negative predictive values for the Uriscreen were estimated using urine culture as the criterion standard. Urine cultures were considered positive if they grew >10(5) colony-forming units of a single uropathogen.

RESULTS

Twenty-eight women (18.7%) had urine culture results indicating significant bacteriuria, and 17 of these 28 specimens had positive enzyme activity. Of 122 samples with no growth, 109 had negative enzyme activity. Sensitivity, specificity, and positive and negative predictive values for the Uriscreen test were 60.7% (+/-18.1), 89.3% (+/-5.6), 56.6%, and 90.8%, respectively.

CONCLUSION

The Uriscreen test had inadequate sensitivity for rapid screening of bacteriuria in pregnancy.

Diabetes Mellitus has no Significant Influence on the Prevalence of Antenatal Asymptomatic Bacteriuria

INTRODUCTION

Diabetes is a known risk factor for asymptomatic bacteriuria (ASB). However, the influence of diabetes on antenatal ASB was previously not addressed.

AIM

The prevalence of ASB, effect of risk factors and type of isolates and susceptibility patterns were studied in diabetic pregnancy.

MATERIALS AND METHODS

A total of 311 pregnant women were recruited for this study of which 103 were diabetic and 208 non-diabetic. A clean catch midstream urine samples were collected and cultured. The isolates were identified and antibiotic sensitivity was studied. The data was analysed by Chi-square test.

RESULTS

The prevalence of ASB in diabetic pregnancy was 38.83% (40/10(3); 95% CI: 23.73 - 53.94) and in non-diabetic pregnancy was 37.98% (79/208; CI: 27.28- 48.68). The odds ratio was not significant 1.0225 (95% CU: 0.65 - 1.599; p=0.922) and associated factors such as age and gestational period had no effect. The major isolates were Escherichia coli (25.0%), Staphylococcus aureus (22.5%), Coagulase negative staphylococci (CONS) (20.00%), and Klebsiella pneumonia (20.00%) in diabetic pregnancy and CONS (31.7%), E.coli (24.0%) and K.pneumonia (16.5%) in non-diabetic pregnancy. The isolates of diabetic pregnancy showed highest susceptibility to nitrofurantoin (56.4%), gentamicin (38.5%) and cotrimoxazole (38.5%) whereas that of non-diabetic pregnancy to gentamicin (43.0%), azithromycin (32.9%) and norfloxacin (30.4). There was no significant (p<0.05) difference in the type and susceptibly of the isolates between diabetic and non-diabetic pregnancy.

CONCLUSION

Diabetes has no significant influence on the prevalence of ASB in diabetic pregnancy both in terms of isolates and antibiotic susceptibility pattern.

Asymptomatic group B streptococcal bacteriuria among pregnant women in Saudi Arabia

This study aims to determine the asymptomatic bacteriuria in pregnancy due to GBS and its antimicrobial sensitivity pattern for planning strategy for the management of these cases and also to determine the relationship between asymptomatic bacteriuria and pyuria. A total of 3863 consecutive urine specimens were collected from 3863 pregnant women with asymptomatic bacteriuria attending the obstetrics and gynaecology department of our hospital over a period of two years. Specimens were processed using standard microbiological procedures. All the subjects were evaluated for bacteriuria. The prevalence of asymptomatic bacteriuria due to group B streptococci (GBS) was 82/3863 (2.1%) among pregnant women in Saudi Arabia. Among these, 69/82 patients (84.2%) had clinical and microbiological features consistent with cystitis, versus 13/82 (15.8%) for pyelonephritis. About 51.2% (42/82) of the patients who had urine analysis performed had positive results based on positive urinary leucocyte esterase and pyuria. Disc-diffusion analysis of all 82 GBS isolates showed that they were highly susceptible to Augmentin and linezolid. Screening for bacteriuria in pregnancy and proper treatment must be considered as an essential part of antenatal care in this community. To prevent asymptomatic bacteriuria complications, all pregnant women should be screened at the first antenatal visit. A negative test for pyuria is not a reliable indicator of the absence of asymptomatic bacteriuria in pregnant women. Further, ongoing surveillance and evaluation of outcomes in pregnancies complicated by GBS bacteriuria is required to optimise maternal and newborn care.

Idiopathic urinary findings and fetal growth restriction in low risk pregnancy

OBJECTIVE

To determine whether maternal urinary findings in the first trimester of pregnancy are associated with fetal growth restriction.

STUDY DESIGN

The prevalence of urinary findings in singleton pregnancies complicated by fetal growth restriction were compared with a low-risk control group of pregnancies who gave birth to normal weight babies, in the same condition.

RESULTS

There were significant statistical differences in the mean gestational age (p < 0.001), isolated asymptomatic bacteriuria (p<0.001), hematuria (p = 0.002, OR = 6.6, CI = 1.8-24.2) and proteinuria (p = 0.016, OR = 4.1, CI = 1.2-13.3). There was no recognizable relation between ketonuria and fetal growth restriction.

CONCLUSION

Our data showed a relation between the increase of adverse pregnancy outcomes, including fetal growth restriction, and hematuria, proteinuria and asymptomatic bacteriuria. Appropriate monitoring of pregnant women using these findings may be helpful in the identification of more complications.

Adherence to evidence-based guidelines for the management of pyelonephritis in pregnancy

BACKGROUND

  Pyelonephritis occurs in approximately two per cent of pregnancies and can cause significant maternal and fetal morbidity and mortality. Evidence-based guidelines recommend appropriate antibiotic therapy, urine culture for test of cure after treatment and monthly follow-up cultures until delivery.

AIMS

  To evaluate adherence to guidelines for the management of antepartum pyelonephritis within an Australian obstetric population and to assess associations with noncompliance.

METHODS

  A retrospective study was performed for the 103 pregnant women admitted with pyelonephritis between January 2001 and December 2009 at the Royal Brisbane and Women's Hospital, a tertiary referral obstetric hospital. We assessed baseline characteristics, the frequency of appropriate treatment and follow-up, and any associations among these.

RESULTS

  The guideline recommended antibiotic treatment was prescribed in 90.3% of women. Of the women with antibiotic-resistant organisms, 31.6% had their antibiotics changed appropriately. The test of cure urine culture was performed in only 35.0% of women after treatment completion. Inadequate long-term follow-up occurred in 60.2% of the cohort studied. Inappropriate follow-up was associated with low socioeconomic status (P=0.04), unemployment (P=0.04) and the absence of a test of cure urine culture (P=0.001).

CONCLUSION

  The empiric treatment of antepartum pyelonephritis is generally appropriate; however, antibiotic changes for bacterial resistance are inadequate. Test of cure and monthly follow-up urine cultures are infrequently performed despite their recommendation in published treatment guidelines.

Maternal urinary tract infection: is it independently associated with adverse pregnancy outcome?

OBJECTIVE

This population-based study was aimed to determine whether there is an association between urinary tract infections (UTI) during pregnancy, among patients in whom antibiotic treatment was recommended, and maternal and perinatal outcome.

METHODS

A retrospective population-based study comparing all singleton pregnancies of patients with and without UTI was performed. Multiple logistic regression models were performed to control for confounders.

RESULTS

Out of 199,093 deliveries, 2.3% (n = 4742) had UTI during pregnancy and delivery. Patients with UTI had significantly higher rates of intra-uterine growth restriction (IUGR), pre-eclampsia, caesarean deliveries (CD) and pre-term deliveries (either before 34 weeks or 37 weeks of gestation). Although controlling for possible confounders such as maternal age and parity, using multivariable analyses, the significant association between UTI and IUGR, pre-eclampsia, CD and preterm deliveries persisted. In contrast, no significant differences in 5-min Apgar scores less than 7 or perinatal mortality were noted between the groups (0.6% vs. 0.6%; p = 0.782, and 1.5% vs. 1.4%; p = 0.704, respectively).

CONCLUSION

Maternal UTI is independently associated with pre-term delivery, pre-eclampsia, IUGR and CD. Nevertheless, it is not associated with increased rates of perinatal mortality compared with women without UTI.

Asymptomatic bacteriuria and symptomatic urinary tract infections in pregnancy

Symptomatic and asymptomatic bacteriuria is common in pregnant women. A history of previous urinary tract infections and low socioeconomic status are risk factors for bacteriuria in pregnancy. Escherichia coli is the most common aetiologic agent in both symptomatic and asymptomatic infection and quantitative culture is the gold standard for diagnosis. Treatment of asymptomatic bacteriuria has been shown to reduce the rate of pyelonephritis in pregnancy and therefore screening for and treatment of asymptomatic bacteriuria has become a standard of obstetrical care. Antibiotic treatment of asymptomatic bacteriuria is associated with a decrease in the incidence of low birth weight, but the methodological quality of the studies limits the strength of the conclusions that can be drawn. Debate exists in the literature as to whether treated pyelonephritis is associated with adverse fetal outcomes. There is no clear consensus in the literature on antibiotic choice or duration of therapy for infection. With increasing antibiotic resistance, consideration of local resistance rates is necessary when choosing therapy.

Maternal serum concentrations of the chemokine CXCL10/IP-10 are elevated in acute pyelonephritis during pregnancy

OBJECTIVE

Acute pyelonephritis is one of the most frequent medical complications of pregnancy, as well as a common cause of antepartum hospitalization. Interferon (IFN)-gamma inducible protein, CXCL10/IP-10, is a member of the CXC chemokine family with pro-inflammatory and anti-angiogenic properties. The purpose of this study was to determine whether maternal serum concentrations of CXCL10/IP-10 change in patients with acute pyelonephritis during pregnancy.

STUDY DESIGN

This cross-sectional study was conducted to determine the difference in maternal serum concentrations of CXCL10/IP-10 in pregnant women with acute pyelonephritis (N = 41) and normal pregnant women (N = 89). Pyelonephritis was defined in the presence of a positive urine culture, fever, and maternal clinical signs; blood cultures were performed in 36 cases. Maternal serum concentrations of CXCL10/IP-10 were measured by a sensitive immunoassay. Non-parametric statistics were used for analysis.

RESULTS

(1) The median serum concentration of CXCL10/IP-10 in pregnant patients with pyelonephritis was significantly higher than in normal pregnant women (median 318.5 pg/mL, range 78.8-2459.2 vs. median 116.1 pg/mL, range 40.7-1314.3, respectively; p < 0.001); (2) maternal median serum concentrations of CXCL10/IP-10 did not differ significantly among patients with acute pyelonephritis with and without bacteremia (positive blood cultures: median 362.6 pg/mL, range 100.2-2459.2 vs. negative blood cultures: median 298.9 pg/mL, range 108.5-1148.7, respectively; p = 0.3).

CONCLUSIONS

Pyelonephritis in pregnant women is associated with an increased maternal serum concentration of the chemokine CXCL10/IP-10.

Asymptomatic bacteriuria and symptomatic urinary tract infections during pregnancy

Urinary tract infections are common complications of pregnancy; upper tract infections in particular may lead to significant morbidity for both the mother and fetus. Bacteriuria is a significant risk factor for developing pyelonephritis in pregnant women. Therefore, proper screening and treatment of bacteriuria during pregnancy is necessary to prevent complications. All women should be screened for bacteriuria in the first trimester, and women with a history of recurrent urinary tract infections or anomalies should have repeat bacteriuria screening throughout pregnancy. Treatment of bacteriuria should include 3-day therapy with appropriate antimicrobials, and women should be followed closely after treatment because recurrence may occur in up to one third of patients.

Is single-dose fosfomycin trometamol a good alternative for asymptomatic bacteriuria in the second trimesterof pregnancy?

Untreated asymptomatic bacteriuria has been associated with acute pyelonephritis, which may have a role in many maternal and fetal complications. Acute pyelonephritis in pregnancy is related to anemia, septicemia, transient renal dysfunction, and pulmonary insufficiency. A randomized study was conducted to assess the clinical and microbiological efficacy of a single dose of fosfomycin trometamol for the treatment of asymptomatic bacteriuria in the second trimester of pregnancy compared with a 5-day regimen of cefuroxime axetyl. Forty-four women received fosfomycin trometamol and 40 women received cefuroxime axetyl. There were no statistically significant differences between both groups regarding the mean age and mean duration of pregnancy. Therapeutic success was achieved in 93.2% of the patients treated with fosfomycin trometamol vs 95% of those treated with cefuroxime axetyl. A single dose of fosfomycin trometamol is a safe and effective alternative in the treatment of asymptomatic urinary tract infections in the second trimester of pregnancy.

Urinary Tract Infections During Pregnancy

OBJECTIVE

To provide a comprehensive review of urinary tract infections (UTIs) during pregnancy. All aspects of UTIs, including epidemiology, pathogenesis, resistance, clinical features, diagnosis, treatment, and prevention, were reviewed.

DATA SOURCES

MEDLINE (1966–August 2003) and Cochrane Library searches were performed using the key search terms urinary tract infection, pyelonephritis, cystitis, asymptomatic bacteriuria, and resistance.

STUDY SELECTION AND DATA EXTRACTION

All article abstracts were evaluated for relevance. Only articles pertaining to pregnancy were included. The majority of published literature were review articles; the number of original clinical studies was limited.

DATA SYNTHESIS

UTIs are the most common bacterial infections during pregnancy. They are characterized by the presence of significant bacteria anywhere along the urinary tract. Pyelonephritis is the most common severe bacterial infection that can lead to perinatal and maternal complications including premature delivery, infants with low birth weight, fetal mortality, preeclampsia, pregnancy-induced hypertension, anemia, thrombocytopenia, and transient renal insufficiency. Enterobacteriaceae account for 90% of UTIs. The common antibiotics used are nitrofurantoin, cefazolin, cephalexin, ceftriaxone, and gentamicin.

CONCLUSIONS

Therapeutic management of UTIs in pregnancy requires proper diagnostic workup and thorough understanding of antimicrobial agents to optimize maternal outcome, ensure safety to the fetus, and prevent complications that lead to significant morbidity and mortality in both the fetus and the mother.

Asymptomatic bacteriuria: when to screen and when to treat

Asymptomatic bacteriuria is common. Populations with structural or functional abnormalities of the genitourinary tract may have an exceedingly high prevalence of bacteriuria, but even healthy individuals frequently have positive urine cultures. Asymptomatic bacteriuria is seldom associated with adverse outcomes. Pregnant women and individuals who are to undergo traumatic genitourinary interventions are at risk for complications of bacteriuria and benefit from screening and treatment programs. Although screening is recommended for renal transplant recipients, the benefits for these patients are less clear. For other populations, including most bacteriuric individuals, negative outcomes attributable to asymptomatic bacteriuria have not been described. Treatment of asymptomatic bacteriuria in these patients is not beneficial and, in fact, may be associated with harmful outcomes, such as increased short-term frequency of symptomatic infection, adverse drug effects, and reinfection with organisms of increased antimicrobial resistance. Screening for asymptomatic bacteriuria and treatment is recommended for only selected groups where benefit has been shown. Many research questions still need to be addressed. Different populations have unique risk factors, and the benefits and risks of different management approaches for asymptomatic bacteriuria must continue to be addressed systematically in appropriate clinical trials.

Renal disease in pregnancy

Women with renal disease who conceive and continue a pregnancy are at significant risk for adverse maternal and fetal outcomes. Risk is inversely related to the degree of renal insufficiency. Pregnancy-induced changes in the urinary tract can temporarily increase renal function compromise, such as nephrosis, but most often results in no net increase in dysfunction. Common complications of pregnancy--such as hypertension and hypovolemia--can be associated with acute renal injury or aggravation of pre-existing disease.

Urinary tract infections during pregnancy

Urinary tract infections are relatively common in pregnancy and may result in significant morbidity for the pregnant woman and fetus. The authors recommend that all pregnant women be screened for the presence of bacteriuria at their first prenatal visit. Failure to treat bacteriuria during pregnancy may result in as many as 25% of women experiencing acute pyelonephritis. Women with acute pyelonephritis may sustain significant complications, such as preterm labor, transient renal failure, ARDS, sepsis and shock, and hematologic abnormalities. Pregnant women with urinary tract infections should be followed up closely after treatment because as many as one third will experience a recurrence.

The acute abdomen and the obstetrician

An acute abdomen in pregnancy can be caused by pregnancy itself, be predisposed to by pregnancy or be the result of a purely incidental cause. These various conditions are discussed. The obstetrician often has a difficult task in diagnosing and managing the acute abdomen in pregnancy. The clinical evaluation is generally confounded by the various anatomical and physiological changes occurring in pregnancy itself. Clinical examination is further hampered by the gravid uterus. The general reluctance to use conventional X-rays because of the pregnancy should be set aside when faced with the seriously ill mother. A reluctance to operate during pregnancy adds unnecessary delay, which increases morbidity for both mother and fetus. Such mistakes should be avoided as prompt diagnosis and appropriate therapy are crucial. A general approach to acute abdominal conditions in pregnancy is to manage these problems regardless of the pregnancy.

Urinary tract infections in pregnancy

Although pregnancy does not increase the prevalence of ASB in women, it does enhance the progression rate from asymptomatic to symptomatic disease. Furthermore, ASB is associated with preterm delivery. Given the fact that identification and eradication of ASB in pregnant women can lower the likelihood of pyelonephritis and prevent preterm delivery, every gravida should be systematically screened for ASB and appropriately treated. In the authors' opinion, a first-trimester urine culture remains the screening test of choice; reliance on symptoms to prompt screening is inadequate because the state of pregnancy can provoke frequency and nocturia. Multiple antibiotic regimens for ASB are safe during pregnancy and effective.

Markers of risk for preterm delivery

Clinical and experimental evidence indicate that PTD results from four primary pathogenic mechanisms: activation of the maternal or fetal HPA axis; amniochorionic-decidual or systemic inflammation; decidual hemorrhage; and, pathologic distention of the myometrium. Each of these four pathways has a distinct epidemiological and clinical profile, and unique biochemical and biophysical pathways initiating parturition, but shares a common final biochemical pathway involving myometrial activation and stimulation, and enhanced genital tract protease activity promoting PPROM and cervical change. Traditional methods of predicting women at risk relying on obstetrical history or symptoms and epidemiological risk factors are neither sensitive nor specific. Recent approaches to predicting PTD, including sonographic measurement of cervical length and biochemical assays for hCG, cytokines, fFN, MMPs, estrogens, and CRH, are more sensitive than traditional methods. Moreover, given the heterogeneous, interactive etiopathogeneses of PTD, multiple biochemical markers should not only increase sensitivity and specificity, but also permit the detection of the relative contribution of each pathogenesis to the overall risk of PTD.

Detection, significance, and therapy of bacteriuria in pregnancy. Update in the managed health care era

Profound physiologic and anatomic changes of the urinary tract during pregnancy contribute to the increased risk for symptomatic urinary tract infection in women with bacteriuria. Asymptomatic bacteriuria is the major risk factor for developing symptomatic UTIs during pregnancy and may be associated with adverse effects on maternal and fetal health. Because most symptomatic UTIs develop in women with bacteriuria earlier in pregnancy, treatment of bacteriuria is undertaken to prevent symptomatic infections. All pregnant women should be screened at the first antenatal visit, which is reliably and inexpensively done with a dipstick culture. Short-course therapy should be given to women with bacteriuria and clearance of bacteriuria should be documented after therapy is complete. Failure to eliminate bacteriuria with repeated therapy or recurrence with the same organism is indicative of renal parenchymal infection or a structural abnormality. All women with persistent bacteriuria or recurrent infection should have follow-up cultures and a urologic evaluation after delivery.

Bacteriuria in pregnancy: a comparison of Bangladeshi and Caucasian women

During a 5-year period all urine culture results from pregnant Caucasian and Bangladeshi women booked for confinement at the Royal London Hospital, London, UK, were reviewed to determine race-specific rates of bacteriuria. The results showed that the overall prevalence of bacteriuria in the Caucasian group was 6.3% compared to 2.0% for the Bangladeshi women. Caucasian women were found to be at significantly greater risk across all pregnancy outcome and history categories, with the greatest risk observed in grand multiparous women (RR: 4.7, 95% CI: 2.8-8.3). Pregnancies that resulted in preterm delivery showed a strong association of bacteriuria in Caucasian women which was not seen in the Bangladeshi women (RR: 4.4, 95% CI: 2.0-8.7). The data suggest that Caucasian women have a significantly higher prevalence of bacteriuria in pregnancy than their Bangladeshi neighbors. Differences in hygiene practices and clothing may explain the observed differences in the bacteriuria rates.

Urinary tract infections complicating pregnancy

Urinary infections, with a spectrum from covert bacteriuria to severe pyelonephritis, commonly complicate pregnancy. Serious infections follow untreated silent bacteriuria in a fourth of cases, and routine screening can be justified in high-risk populations, particularly in those women from lower socioeconomic strata. Despite an initial salutary response to a number of antimicrobial regimens, covert bacteriuria recurs in one-third of treated women whose risk of pyelonephritis again is at 25%. Acute cystitis may be unrelated to these other infections and responds readily to a number of regimens; however, single-dose therapy is not recommended because early pyelonephritis can be mistaken for uncomplicated cystitis. Pyelonephritis is the most common severe bacterial infection complicating pregnancy. These women are frequently quite ill, and hospitalization is recommended. Since 85-90% respond within 72 h to intravenous fluids and antimicrobials, continued fever and evidence for sepsis should prompt a search for underlying obstruction. Perhaps 20% of women with severe pyelonephritis develop complications that include septic shock syndrome or its presumed variants. These latter include renal dysfunction, haemolysis and thrombocytopenia, and pulmonary capillary injury. In most of these women, continued fluid and antimicrobial therapy result in a salutary outcome, but there is occasional maternal morbidity.

Urinary tract infection during pregnancy: its association with maternal morbidity and perinatal outcome

OBJECTIVES

The effects of antepartum urinary tract infection on adverse maternal and perinatal outcomes were examined. Antepartum urinary tract infection has been previously implicated as a risk factor for numerous outcomes.

METHODS

Crude and multivariable analyses were performed with a perinatal registry cohort of 25,746 mother/infant pairs.

RESULTS

Elevated risks were observed for exposure to urinary tract infection and low birthweight, prematurity, preterm low birthweight, premature labor, hypertension/preeclampsia, maternal anemia, and amnionitis. Urinary tract infection was associated with perinatal death only among subjects 20 to 29 years of age.

CONCLUSIONS

These findings underscore the importance of antepartum urine screening to identify patients at risk for adverse outcomes.

Uterine contractions after antibiotic therapy for pyelonephritis in pregnancy

OBJECTIVE

The purpose of our study was to investigate the pathogenesis of preterm labor in pyelonephritis, we determined the number of uterine contractions occurring in patients with pyelonephritis before and after antibiotic therapy.

STUDY DESIGN

We recorded the uterine contractions before and after antibiotic administration in 30 patients with acute pyelonephritis at Lyndon B. Johnson Hospital in Houston. Exclusion criteria were cervical dilatation > or = 4 cm, < 26 weeks' gestation, antibiotics within 7 days, clinical intraamniotic infection, rupture of membranes, or other maternal infection. Statistical analysis was by Kruskal-Wallis analysis of variance and Wilcoxon rank sum tests.

RESULTS

The patients averaged eight contractions per hour on admission. The contraction rate significantly increased in hours +1 to +4 after antibiotic administration. The increase in uterine contractility occurred in patients with urinary tract gram-negative isolates.

CONCLUSIONS

Pregnant women with pyelonephritis resulting from gram-negative bacteria increase their rate of uterine contractility after antibiotic treatment. This observation may be important in understanding the pathogenesis of preterm labor in pyelonephritis.

Epidemiology, natural history, and management of urinary tract infections in pregnancy

The urinary tract undergoes profound physiologic and anatomic changes during pregnancy that facilitate the development of symptomatic UTIs in women with bacteriuria. Although the adverse effects of asymptomatic bacteriuria on maternal and fetal health continue to be debated, it is clear that asymptomatic bacteriuria is the major risk factor for developing symptomatic UTI and that symptomatic infections are associated with significant maternal and fetal risks. Because the majority of symptomatic UTIs develop in women with bacteriuria earlier in pregnancy, treatment of bacteriuria is undertaken to prevent symptomatic infections. All women should be screened at the first antenatal visit, which is reliably and inexpensively done with a dipstick culture. Short-course therapy is as effective as prolonged therapy and should be followed with a repeat culture to document clearing of the bacteriuria. Failure to eliminate bacteriuria with repeated therapy or recurrence with the same organism is indicative of renal parenchymal infection or a structural abnormality. All women with persistent bacteriuria or recurrent infection should have follow-up cultures and a complete urologic evaluation after delivery.

Mechanisms of hemolysis and anemia associated with acute antepartum pyelonephritis

Anemia develops in about a fourth of women whose pregnancy is complicated by pyelonephritis, although its exact mechanism has not been defined clearly. In this study of 18 women with antepartum pyelonephritis, although only a third had anemia (hematocrit less than 30 vol/dl), there was evidence for hemolysis in all 18. Specifically there was a mean decrease in hematocrit of 5 vol/dl from admission to discharge. With scanning electron microscopy, we compared erythrocyte morphologic aberrations that were found in women with renal infection with those of normally pregnant women, and the former had significantly increased proportions of echinocytes in particular, but schistocytes and spherocytes were increased also (total 10.3% vs 1.4%, p less than 0.0001). These changes, especially echinocytosis, have been induced in vitro by lipopolysaccharide, and they are known to lead to premature red blood cell destruction in vivo. We conclude that hemolysis with subsequent anemia in pregnant women with pyelonephritis is caused by lipopolysaccharide-induced red blood cell membrane damage.

Urinary tract infections complicating pregnancy

Urinary infections, with a spectrum from covert bacteriuria to severe pyelonephritis, commonly complicate pregnancy. Serious infections follow untreated silent bacteriuria in a fourth of cases, and routine screening can be justified in high-risk populations, particularly those from lower socioeconomic strata. Despite an initial salutary response to a number of antimicrobial regimens, covert bacteriuria recurs in one-third of treated women whose risk of pyelonephritis remains at 25%. Acute cystitis may be unrelated to these other infections and responds readily to a number of regimens; however, single-dose therapy is not recommended since early pyelonephritis can be mistaken for uncomplicated cystitis. Pyelonephritis is the most common severe bacterial infection complicating pregnancy. These women are frequently quite ill, and hospitalization is recommended. Since 85% to 90% respond within 48 hours to intravenous fluids and antimicrobials, continued fever and evidence of sepsis after two or three days should prompt a search for underlying obstruction. Perhaps 20% of women with severe pyelonephritis develop complications that include septic shock syndrome or its presumed variants. These latter include renal dysfunction, haemolysis and thrombocytopaenia, and pulmonary capillary injury. In most of these women, continued fluid and antimicrobial therapy result in a salutary outcome, but there is occasional maternal mortality.

Reasons for failure of antihypertensive treatment

One hundred patients whose hypertension was originally well controlled were carefully screened when a routine clinic visit showed that their blood pressure was above 170/100 mm Hg. Simple misconceptions accounted for 75 failures: 38 did not know they had to continue their drugs, 14 thought they should not take antihypertensive drugs if they had not had a meal, 13 did not know which drugs controlled their blood pressure, and 10 believed it was better not to take their drugs on clinic days. Eleven patients were using racemic alpha-methyldopa, which was ineffective; 11 others said they could not afford the drugs; only three intentionally stopped their drugs because of unpleasant side effects. Patients need to be thoroughly informed about their treatment and the number of drugs kept to a minimum.