Lung Volume Head Ratio: A Potential Parameter for Prediction of Respiratory Distress in Newborn

Abstract

Objective: To evaluate the role of fetal lung biometry profile including fetal lung volume head ratio (LVHR) in predicting the occurrence of respiratory distress (RD) in early preterm newborn. Material and Method: Prospective analytical cohort study was done to evaluate the clinical value of fetal sonographic measures such as the total lung area (TLA), total lung volume (TLV), total lung area head ratio (TLHR), lung volume head ratio (LVHR) was measured in pregnant women between 30 to 34 week gestation , expected to deliver within the next 72 hours. The cases with RD were compared with controls who had normal outcome. Result: Total 30(27.4%) out of 110 subjects undergoing early preterm delivery had RD rest 80(72.6%) were controls. The total lung area was 694.1±373.1 mm2 in cases whereas 1149.0 ± 506 .7 mm2 in controls, with significant difference between the two groups(p<0.001). Similarly the lung volume (p<0.001) and the lung volume head ratio was significantly less (P<0.001) in cases compared to controls. The total lung volume was a better parameter (sensitivity-73.7%; specificity-86.4%) compared to total lung area (Sensitivity - 68.4%, Specificity - 81.5%). Among the lung head ratios, LVHR had best sensitivity - 95.5%, Specificity - 80.3%, PPV-58.3%, NPV - 97.0% at the cut off of 46.5. Conclusion: Respiratory distress was observed in nearly one-third of the preterm infants born between 30 and 34 weeks and could be predicted accurately in over nine out of ten cases using the novel parameter TLVR.