Conventional IAI Diagnostic Tools Have Limitations

Despite the increasing awareness of the importance of the diagnosis and treatment of IAI in preterm labor, detection of IAI can be difficult because 80% to 90% of all cases have no clinical signs or symptoms.¹⁰ In addition amniocentesis and commonly available laboratory diagnostic tests with AF have limitations:

• Two of the most common causative pathogens of IAI (Mycoplasma and Ureaplasma species) are present in 30% to 50% of cases. Tests to detect these pathogens are rarely available in clinical laboratories.

• 48 to 72 hours are needed for complete aerobic and anaerobic AF culture results.

• AF Gram stain and glucose concentration tests have relatively poor sensitivity. In a pooled analysis of 6 studies, Gram stain demonstrated average sensitivity of 48%. Glucose concentration demonstrated sensitivity of 63% to 87%.

• Previous antibiotic use can result in the inability of culture to detect pathogenic organisms.

In the absence of clinical symptoms, and given the limitations of current IAI diagnostic tools, routinely assessing PTL patients for IAI can be difficult and cases of IAI can remain undiagnosed and untreated.¹¹