Serial ultrasonographic examination of the fetal thymus in the prediction of early neonatal sepsis in preterm premature rupture of membranes.

ABSTRACT

BACKGROUND/AIMS: To evaluate the diagnostic accuracy of fetal thymus transverse diameter (FTTD) in predicting fetal infection in preterm premature rupture of membranes (PPROM) and compare its accuracy with cord blood tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). METHODS: Forty consecutive pregnancies complicated with PPROM between 26(1/7) and 36(6/7) gestational weeks were evaluated prospectively. Serial fetal ultrasonography follow-ups with 3-day intervals were performed beginning on the admission day. The FTTD was recorded on every ultrasonographic examination. Cord blood TNF-α and IL-6 values were measured after delivery. RESULTS: FTTD was decreased below 5% according to nomograms compared to the initial measurement in 45% of all PPROM cases. Decreased FTTD had a sensitivity of 100%, specificity of 73%, positive predictive value of 55%, and negative predictive value of 100% in predicting early neonatal sepsis. Cord blood TNF-α had a sensitivity of 80% and specificity of 90%, whereas IL-6 had a sensitivity of 90% and specificity of 63.3% in predicting early neonatal sepsis. CONCLUSIONS: Assessment of the decrease in FTTD by serial ultrasonographic examinations is a promising 'prenatal' method for the early detection of early neonatal sepsis.