A retrospective observational study of cord blood procalcitonin as a routine screening tool for the diagnosis of early onset neonatal sepsis in neonates born to mothers after assisted fertility

Early onset neonatal sepsis (EONS) has been a major cause of morbidity and mortality in neonates , the clinical signs of early-onset neonatal sepsis (EONS) are nonspecific, sometimes late to develop, and indistinguishable from those of noninfectious disorders. The early diagnosis of EONS is difficult but is essential to improve outcomes. Early onset neonatal sepsis must be diagnosed while the patient is still asymptomatic. Such a diagnosis would rest on the identification of NBs at risk of early-onset sepsis.

Neonates born to mothers who are treated for infertility have an increased risk of preterm delivery, multiple pregnancies, and premature rupture of membranes (PROM). Each one of them individually is a risk factor for neonatal sepsis

In our assisted fertility center, we have observed a similar pattern, and few cases resulted in EONS without risk factors.  Blood culture is the gold standard for the diagnosis of neonatal sepsis but takes a long time. Clinical diagnosis is difficult and rather late to appear.

Biochemical  markerslike Neutropenia, Thrombocytopenia, Immature neutrophils (Band cells + myelocytes + metamyelocytes) to total neutrophils ratio (l/T) > 0.20,  C-reactive protein(CRP), neonatal procalcitonin, Interleukin (IL) 6 & IL 8, serum amyloid A, Tumor necrosis Factor (TNF) α have their own limitations and some more are in evaluative phase

Procalcitonin (PCT) is a prohormone secreted by most parenchymal tissues. Recent studies demonstrate that cord blood PCT levels could be used to discriminate between septic and nonseptic neonates at an early stage. The derived cutoff values of PCT used in the cord blood studies ranged from 0.5 to 1.22ng/mL.

Operating curves of PCT determined 0.6 ng/ml as the best cut-off (immunoâ€chromatographic semiquantitative test). The sensitivity, specificity, and negative and positive predictive values were respectively 87.5%, 98.7%, 87.5%, and 98.7% for PCT.  It also presents good positive and negative likelihood ratios and appears to be more reliable than CRP. We have planned a retrospective observational study of the cord blood procalcitonin to use this as a screening tool in diagnosis of EONS.