Intrapartum fever (IF) accompanied by either maternal or foetal tachycardia, elevated WBC, or purulent discharge is classified as "suspected triple 1", the hallmark of intraamniotic infection (IAI). Poor specificity of the clinical diagnosis of IAI results, in retrospect, in the unnecessary treatment of most parturients and neonates. We studied the yield of specific acute phase reactants (APRs): procalcitonin, CRP, IL-6, in detecting bacterial IAI among parturients classified as "suspected triple 1" (cases) compared to afebrile parturients (controls). Procalcitonin, CRP, and IL-6 were all significantly elevated in the cases compared to the controls, yet this by itself was not sufficient for an additive effect in detecting a bacterial infection among parturients clinically diagnosed with "suspected triple 1", as demonstrated by the poor area under the receiver operating characteristic curve of all three APRs.