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Urinary Tract Infections During Pregnancy


Lara A. Friel

, MD, PhD, University of Texas Health Medical School at Houston, McGovern Medical School

Last full review/revision Jun 2021| Content last modified Jun 2021
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Urinary tract infections Overview of Urinary Tract Infections (UTIs) In healthy people, urine in the bladder is sterile—no bacteria or other infectious organisms are present. The tube that carries urine from the bladder out of the body (urethra) contains no bacteria... read more are common during pregnancy, probably because the enlarging uterus and hormones produced during pregnancy slow the flow of urine in the tubes that connect the kidneys to the bladder (ureters). When urine flow is slow, bacteria may not be flushed out of the urinary tract, increasing the risk of an infection.

Urinary tract infections increase the risk of the following:

Sometimes bacteria in the urine cause an infection in the bladder or kidneys Postpartum Bladder and Kidney Infections A bladder infection (cystitis) sometimes develops after delivery of a baby. A kidney infection (pyelonephritis) can occur if bacteria spread from the bladder to the kidney after delivery. Bladder... read more that causes symptoms. But bacteria may infect the urine without causing symptoms of urinary tract infections, so doctors usually check the urine for bacteria, even in pregnant women without symptoms. If pregnant women have bacteria in the urine or a kidney infection, a urine sample is taken each month and tested.

Treatment of urinary tract infections consists of antibiotics. Doctors commonly use cephalexin, nitrofurantoin, or trimethoprim/sulfamethoxazole. Nitrofurantoin and trimethoprim/sulfamethoxazole are used only during the 1st trimester when no other alternatives are available. Women who have had more than one bladder infection or have had a kidney infection need to take antibiotics throughout pregnancy to prevent subsequent urinary tract infections.

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