EXPLANATION FOR QUESTION 27

 QUESTION 27


The patient has asymptomatic bacteriuria (ASB), the growth of ?.100,000 (105) colony-forming units/ml of a single bacteria from a

clean catch urine specimen from a patient who has no urinary tract infection symptoms (eg, dysuria, urinary frequency) In pregnancy,

increased progesterone levels cause smooth muscle relaxation and ureteral dilation. Because of these physiologic changes,

patients with untreated ASB during pregnancy are at increased risk for ascending infection (eg, acute pyelonephritis). ASB in

pregnancy is also associated with an increased risk of preterm labor and low birth weight

Because of the risk of pyelonephritis and other complications, all women are screened for ASB with a urine culture at the initial

prenatal visit. ASB in pregnancy requires treatment; first-line antibiotics include cephalexin, amoxicillin-clavulanate, and

nitrofurantoin. The most common pathogen associated with ASB is Escherichia coli. As a test of cure, a repeat urine culture is

performed after antibiotic treatment is completed

(Choice A) Abruptio placentae, the premature separation of the placenta from the uterine wall, is associated with preeclampsia,

maternal abdominal trauma, and cocaine use, none of which are seen in this patient

(Choice C) Cervical insufficiency refers to painless cervical dilation that causes second trimester pregnancy loss. Risk factors

include a history of cervical trauma and cervical surgery (eg, conization). There is no association with ASB.

(Choice D) Chorioamnionitis is due to the ascent of normal vaginal flora into the uterus. Risk factors include prolonged membrane

rupture, operative vaginal delivery, and group B Streptococcus colonization, not ASB.

(Choice E) A protracted first stage of labor is most commonly dU1e to fetal macrosomia, which is commonly associated with

gestational diabetes mellitus. This patient's glucose challenge test is normal (<140 mg/dl)

(Choice F) Oligohydramnios is associated with hypertension and placental insufficiency but not with ASB.

(Choice G) Preeclampsia is associated with diabetes mellitus, hypertension, renal disease, and extremes of maternal age, none of

which are seen in this patient

Educational objective:

Asymptomatic bacteriuria is diagnosed when a clean catch urine ,culture from an asymptomatic patient grows �100,000 colonyforming units/ml of a single organism Due to the increased risk of pyelonephritis during pregnancy, all patients should be screened

for asymptomatic bacteriuria during their first prenatal visit and be treated as indicated.

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