Urinary tract infection in gynaecology and obstetrics

Urinary tract infections in pregnancy

Pregnancy is considered a risk factor for UTIs because of the hormonal (largely due to progesterone), functional and anatomical changes associated with it. This includes diminished bladder tone; decreased ureteral peristalsis – mainly from the third month of gestation; hyperaemia and oedema of the bladder mucosa; and dilatation of ureters, vesicoureteral reflux into the renal pelvis. The enlarging uterus causes external compression of the ureters with particularly the right ureter being affected due to dextro-rotation of the uterus. All of these changes contribute to common urinary complaints during pregnancy, such as frequency, nocturia and incontinence.

Recurrent urinary tract infections in pregnancy

Pregnant women who have recurrent UTIs should use prophylactic antibiotics. A single, postcoital dose or daily suppression with cephalexin or nitrofurantoin is an effective preventative therapy. Hydronephrosis and urolithiasis are frequent. The urological postpartum evaluation may be necessary for patients with recurrent UTIs. Postcoital prophylaxis should be considered in pregnant women with a history of frequent UTIs before the onset of pregnancy, to reduce their risk of UTI.

Urinary tract infections in gynaecology

Urinary tract infection is one of the main differentials for pelvic pain in a gynaecological patient. In addition, UTIs must be excluded before diagnoses of overactive bladder or bladder pain syndrome are made. Asymptomatic bacteriuria is not treated in this group of women or those with catheters in situ. Women of any age with symptoms or signs of uncomplicated acute lower UTI should be treated with a three-day course of trimethoprim or nitrofurantoin after taking into consideration the local antibiotic resistance patterns. Particular care should be taken when prescribing nitrofurantoin to elderly patients, who may be at increased risk of toxicity. Post-coital single-dose antibiotic therapy has been proven to be as effective as a continuous daily treatment and has the benefits of less antibiotic use (reducing the risk of resistance). Some women find “self-start therapy” a useful option, whereby they commence antibiotics themselves at the first signs of a UTI in cases of episodic recurrence.

Disease management and follow-up

Prevention of UTIs includes counselling regarding avoidance of risk factors, non-antimicrobial measures and antimicrobial prophylaxis. These interventions should be attempted in this order. Any urological risk factors must be identified and treated. Significant residual urine should be treated optimally, including by clean intermittent catheterisation.

Recurrent UTI in postmenopausal women

The prevalence of UTI increases with age with postmenopausal women being disproportionately affected. Women over 65 years of age develop UTIs at double the rate seen in the female population overall. While coitally associated UTIs occur, these are less common in postmenopausal women. Additional specific risk factors for postmenopausal women include the history of premenopausal UTI, cystocele, and blood group antigen secretory status. Menopause is a predominant risk factor for UTI because of the changes in the urogenital microbiome associated with oestrogen deficiency, often reducing a woman’s natural defence mechanisms against UTI, as discussed earlier. Apart from the classic symptoms of ‘cystitis’, older women may report other symptoms as well, including foul odour, incomplete emptying, constipation, haematuria, generally feeling ‘ill’, and altered mental status. Pelvic examination is not required for postmenopausal women prior to treatment for infrequent, sporadic UTI. However, in postmenopausal women with an uncertain diagnosis or consideration of frequent/recurrent UTI, the pelvic examination should assess oestrogen adequacy in urogenital tissues and search for other findings that would alter planned therapy, such as suburethral masses, pelvic organ prolapse, foreign bodies, or fistulous tracts. Since decreased detrusor muscle function increases with age, a post-void residual volume should be obtained to assess for incomplete emptying, which can be a cause for lower urinary tract symptoms as well as UTI. Restoring the urobiome to its protective state and avoiding dysbioses are key in preventing UTI. Alterations to the protective state of the urobiome can also be caused by certain behaviours and hygienic practices. Smokers have decreased vaginal lactobacilli; vaginal moisturizers, personal lubricants, douches, and spermicides suppress the growth of Lactobacillus in vitro. Vaginal oestrogen replacement reduces the UTI risk, a beneficial effect not seen with oral. As a final caveat, infections in post-menopausal women with recurrent UTIs should be treated, but appropriate patients should also be started on vaginal oestrogen replacement.

Hospital-acquired urinary tract infections (HAUTIs)

Healthcare-associated UTIs are the most common and the largest subtype among all healthcare-associated infections being responsible for 40e60% of these infections. Over 4 million patients acquire healthcare-associated infections in the European Union every year, 20 30% of which are considered preventable. Increased age of patients and co-morbidity renders hospitalized patients susceptible to infection. Aetiology in this age group varies by health status with factors such as catheterization affecting the likelihood of infection and the pathogens most likely to be responsible. Even in neonates, however, hospital-acquired UTIs can represent serious disease and cause severe complications. Hospital-acquired UTIs are almost exclusively complicated UTIs and consist of a very heterogeneous group with a common feature of complicating factors like anatomical, structural or functional alterations in the urinary tract, which have a urodynamic impact, impairment of renal function by renal, pre- or postrenal nephropathies and/or accompanying diseases which deteriorate the immune system. In the case of women with urinary catheters, classical clinical symptoms or signs cannot be relied upon for predicting the likelihood of symptomatic UTI and urine dipstick testing cannot be used to diagnose UTI in them. Routine prescription of antibiotic prophylaxis to prevent symptomatic UTI in these women is not recommended. The bacteria show great diversity with multi-resistance and altered virulence factors. Single antibiotic therapy may not be sufficient and complicating factors should be treated in addition. Relapse of infection by the same strain is frequent. Hospital-acquired urinary tract infections can merge into severe infections such as urosepsis and septic shock. The microbiological spectrum encompasses multi-resistant bacteria, thus microbiological sampling prior to therapy is mandatory. Additionally, the complicating factors must be diagnosed and treated adequately. The best prophylaxis is to minimize the duration of the urinary catheter and to employ general hygienic procedures.

Author: Priyanka H Krishnaswamy Maya Basu