Two Cases of Catheter-Related Bloodstream Infection: A Previously Unreported Complication of Long-Term Ritodrine Tocolysis

Prolonged use of ritodrine hydrochloride (RT) for threatened preterm labor is discouraged in Western countries due to a lack of proven efficacy and severe maternal risks; however, it remains common in Japan. We report two rare cases of catheter-related bloodstream infections (CRBSI) in pregnant women undergoing long-term peripheral-line RT infusion. The first case involved <i>Stenotrophomonas maltophilia</i> bacteremia, a multidrug-resistant pathogen rarely reported in pregnancy. Despite limited antibiotic options, the patient recovered and delivered a healthy infant. The second case involved <i>Achromobacter xylosoxidans</i> bacteremia, treated successfully with ceftazidime, resulting in favorable maternal and neonatal outcomes. Both pathogens are opportunistic, typically affecting immunocompromised hosts or patients with indwelling devices, and their occurrence in otherwise healthy pregnant women underscores the risks of long tocolysis. These cases highlight CRBSI as a potentially life-threatening complication of long-term intravenous RT and emphasize the need to carefully balance its use against adverse outcomes.