From the Guidelines

Yes, a pregnant woman with bacteriuria due to Staphylococcus epidermidis, with a significant bacterial load, should be treated.

The Infectious Diseases Society of America recommends screening for and treating asymptomatic bacteriuria (ASB) in pregnant women to decrease the risk of pyelonephritis and potentially reduce the risk of low birth weight and preterm labor 1.
Antimicrobial treatment has been shown to reduce the risk of pyelonephritis in pregnant women with ASB, from 20%–35% to 1%–4% 1.
The US Preventive Services Task Force also recommends screening for ASB in pregnant women, as it significantly reduces the incidence of symptomatic maternal urinary tract infections and low birth weight 1.
The recommended treatment duration is 4–7 days of antimicrobial treatment, although the optimal duration may vary depending on the antimicrobial given 1.
It is essential to note that Staphylococcus epidermidis is not typically considered a common cause of urinary tract infections, and the treatment approach may vary depending on the specific circumstances and the results of urine culture and sensitivity testing.
However, given the potential risks associated with untreated bacteriuria in pregnancy, treatment is generally recommended, and the choice of antibiotic should be guided by the results of culture and sensitivity testing, as well as considerations of maternal and fetal safety.

From the Research

Bacteriuria during pregnancy, including asymptomatic bacteriuria, should be treated to prevent the development of symptomatic urinary tract infections, such as pyelonephritis, which can have adverse effects on maternal and fetal health 2, 3.
The treatment of bacteriuria in pregnancy reduces the risk of subsequent development of symptomatic disease, including acute pyelonephritis 4.
All pregnant women with bacteriuria, including those with asymptomatic bacteriuria, should be treated with antimicrobial therapy, with the choice of antibiotic reflecting safety for both the mother and the fetus 2, 5.

Nitrofurantoin may be a good choice for the treatment of urinary tract infections in pregnancy due to its low resistance rate, but it should be used with caution 5.
The choice of antibiotic should be based on antimicrobial susceptibility testing, and follow-up cultures should be used to detect recurrence or relapse 4.

A short-course (four- to seven-day) regimen of antibiotics may be more effective than a single-dose regimen for the treatment of asymptomatic bacteriuria in pregnancy, although more evidence is needed to confirm this 6.
Single-dose therapy may be less effective than a short-course regimen, but it has the advantages of improved compliance, reduced costs, and fewer adverse effects resulting from long-term therapy 4.

Follow-up cultures should be used to detect recurrence or relapse after treatment of bacteriuria in pregnancy, and a repeat course of antimicrobial therapy should be chosen based on antimicrobial susceptibility testing if bacteriuria is present 4, 3.
Women with persistent bacteriuria or recurrent infection should have follow-up cultures and a complete urologic evaluation after delivery 3.