武功密笈

小黃藏書

v Approximately 5% to 7% of pregnant women have asymptomatic bacteriuria

at their first prenatal visit.

v Prior colonization rather than new infection

? Socioeconomic status

‚ Sickle cell disease

ƒ Anatomic abnormalities of the urinary system

„ Conditions associated with neurogenic urinary retention, such as spinal cord

injuries or multiple sclerosis

… Diabetes

† A history or UTI

‡ Pregnancy itself, secondary to the urostasis effect of progesterone and the

obstructive effect of the gravid uterus

v Asymptomatic bacteriuria predisposes pregnant patients to pyelonephritis and

potential complications such as sepsis, renal dysfunction, and preterm labor

with all its sequelae for the newborn.

v Without treatment, up to 50% of these women will develop symptomatic

UTI ? that is, pyelonephritis ? during the pregnancy.

v Recurrence of bacteriuria occurs in 10% to 40% of pregnant women treated

for bacteriuria.

　

v Gram-negative rods: 90%

- Escherichia coli (the most common organism isolated)

- Klebsiella sp, Enterobacter sp, and Proteus sp.

v Others: Group B streptococci and Staphylococcus saprophyticus

v Culture and susceptibility testing are the standard means of diagnosing and

managing UTI during pregnancy.

ø Definition of bacteriuria:

- for first-void midstream clean-catch urine specimens:

– Presence of more than 10⁵ CFU/mL from two consecutive specimens

- for a non-first-void specimens:

– Presence of more than 10² CFU/mL of a single pathogen

v Nonculture testing:

Leukocyte esterase and microbe-produced nitrites by urine dipstick

v Testing for Neisseria gonorrhoeae and Chlamydia trachomatis

　

Indication	Regimen
Trimethoprim/sulfamethoxazole (BaktarR) (80/400)	2# bid	7-10 days, except near term
Nitrofurantoin (MacrodantinR) (100)	0.5-1# q6-8h	7-10 days
Amoxicillin (250)	2# q8h	7-10 days
Cephalexin (KeflexR) (250, 500)	250-500 mg q6h	7-10 days
Nitrofurantoin (MacrodantinR) (100)	0.5-1# qd, or 0.5# bid
Cephalexin (KeflexR) (250, 500)	250-500 mg bid

ø Sulfonamides:

- Used with caution close to delivery because of their potential for

displacing fetal bilirubin and inducing kernicteris.

- May produce fetal hemolytic anemia in G6PD deficiency.

ø Nitrofurantoin:

- May produce fetal hemolytic anemia in G6PD deficiency.

- Very effective

ø Quinolones should be avoided in pregnancy.

ø Cephalosporins;

- Should not be use for single-dose treatment owing to high failure rate

(40%)

ø Regardless of the regimen, a follow-up test of cure is mandatory.

Asymptomatic bacteriuria in a pregnant patient can cause pyelonephritis

and complications such as sepsis, renal dysfunction, and preterm labor.

Appropriate screening and management prevents such adverse outcomes.