Prevalence Of Urinary Tract Infection During Pregnancy

Urinary tract infections (UTI) are the most common bacterial infections during pregnancy . Untreated UTI can be associated with serious obstetric complications. This cross-sectional study was carried out to determine the prevalence of UTI among pregnant women attending in two private tertiary medical college hospital of Dhaka. A total of 250 pregnant women were enrolled in this study. UTI was diagnosed using mid stream urine (MSU) culture. Using > 10 colony forming unit per milliliter as significant level of bacteriuria, the prevalence was found to be 26.0%. There was a high incidence in 21–25 years age group (44.61%). There was also high incidence of infection in the third trimester of pregnancy (78.46%) comparid to first (9.23%) and second trimester (12.30%). Multiparty is associated with increased urinary tract infection in pregnancy. Regarding education 10% were literate and 90% were illiterate. Prevalence of bacteriuria was 94% in women who had past history of urinary tract infection. 80% were sexually active. E.coli was the most frequently isolated pathogen (88.15%).These findings underscores the importance of screening all pregnant women for significant bacteriuria, so that positive cases should be treated subsequently with antibiotics in order to reduce the adverse effects on both maternal and fetal health . Introduction Urinary tract infections (UTI), which are caused by the presence and growth of microorganisms in the urinary tract, are perhaps the single commonest bacterial infections of mankind 1 and in pregnancy, it may involve the lower urinary tract or the bladder . UTI has been reported among 20% of the pregnant women and it is the most common cause of admission in obstetrical wards. Anatomically UTI can be classified into lower urinary tract infection involving the bladder and urethra and upper urinary tract infection involving the kidney, pelvis, and ureter. The majority of the UTI occur due to ascending infection . Three common clinical manifestations of UTIs in pregnancy are: asymptomatic bacteriuria, acute cystitis and acute pyelonephritis. UTI is defined as the presence of at least 100,000 organisms per milliliter of urine in an asymptomatic patient, or as more than 100 organisms/mL of urine with accompanying pyuria (>5 WBCs/mL) in a symptomatic patient. Particularly in asymptomatic patients, a diagnosis of UTI should be supported by a positive culture for a uropathogen . Untreated asymptomatic bacteriuria is a risk factor for acute cystitis (40%) and pyelonephritis (25-30%) in pregnancy. These cases account for 70% of all cases of symptomatic UTI among unscreened pregnant women. Symptomatic and asymptomatic bacteriuria have been reported among 17.9% and 13.0% pregnant women, respectively . Pregnancy increases the risk of UTI. At around 6th week of pregnancy, due to the physiological changes of pregnancy the ureters begin to dilate. This is also known as "hydronephrosis of pregnancy", which peaks at 22-26 weeks and continues to persist until delivery. Both progesterone and estrogens levels J. Dhaka National Med. Coll. Hos. 2011; 17 (02): 8-12 9 increase during pregnancy and these will lead to decreased ureteral and bladder tone. Increased plasma volume during pregnancy leads to decrease urine concentration and increased bladder volume. The combination of all these factors lead to urinary stasis and uretero-vesical reflux. Additionally, the apparent reduction in immunity of pregnant women appears to encourage the growth of both commensal and non-commensal microorganisms . The physiological increase in plasma volume during pregnancy decreases urine concentration and up to 70% pregnant women develop glucosurea, which encourages bacterial growth in the urine . Female gender itself is a risk factor because of short urethra, its proximity to vagina and anus and inability of women to empty their bladder completely. High incidence is seen in lower socioeconomic group . Sexual activity and certain contraceptive methods are also said to increase the risk. The anatomical relationship of female’s urethra and the vagina makes it liable to trauma during sexual intercourse as well as bacteria been massaged up the urethra into the bladder during pregnancy/child birth.Abnormalities of urinary tract or stones, diabetes mellitus, immunosupression and past history of UTI tend to increase the risk . Urinary tract infection during pregnancy contributes significantly to maternal and perinatal morbidity . Abortion, small birth size, maternal anemia, hypertension, preterm labour, phlebitis, thrombosis and chronic pyelonephritis are related to urinary tract infection during pregnancy . E. coli remains the predominant organism implicated in urinary tract infection in pregnancy, though recent reports show changes in pattern of the infection. Recent studies in Nigeria show an increasing involvement of Klebsiella Spp. Staphylococcus aureus, Proteus spp., and Pseudomonas spp. in urinary tract infection in pregnancy . Studies have also shown that treatment of bacteriuria during pregnancy reduces the incidence of these complications 21 and lowers the long-term risk of sequelae following asymptomatic bacteriuria 22. Materials And Methods This cross-sectional study was conducted in two private tertiary Medical College hospital of Dhaka (Gynaecology and obstetric department) between January 2009 to January 2011. Consecutive booked antenatal women who presented at the antenatal clinics of the above mentioned hospital during the study period were randomly recruited into the study upon informed consent, either had any of the symptoms suggestive of urinary tract infections or without any symptoms. A consecutive 250 pregnant women with or without symptoms of UTI were included in this study. Pregnant women having renal disease or on antibiotic therapy within 72 hours to the study days were excluded due to the fact that the antibiotic must have inhibited or destroyed the pathogens. Verbal informed consent was obtained from each women before the commencement of the research. Socio-demographic data such as age, occupation, pariety and duration of gestation were collected from the pregnant women using standard questionnaires and kept confidential during the research. Early morning clean-catch midstream urine was collected from each pregnant women into a wide-mouthed sterile screwcapped container. With a Calobrated micro-loop 0.001 ml. of urine was cultured on to a Blood agar & a MacConkey agar plate. After overnight incubation at 37o C for 24 hours, colony counts yielding bacterial growth of ≥10 / ml was taken as being significant in both symptomatic and asymptomatic pregnant women. Centrifuged urine deposit was examined microscopically at high magnification for pus cells, red blood cells, epithelial cells, casts, crystals, yeast-like cells. Pus cells >5/HPF were also considered significant for infection. On the basis of family income, women were divided in low (less then Tk. 5000/month, middle Tk. 5000 to Tk.15000 and upper social class more than Rs.15000 per month or more respectively.