Combined measurement of fetal lung volume and pulmonary artery resistance index is more accurate for prediction of neonatal respiratory distress syndrome in preterm fetuses: a pilot study

Abstract

Objective: The objective of this study is to estimate optimal cut-off values for mean fetal lung volume (FLV) and pulmonary artery resistance index (PA-RI) as non-invasive measures to predict neonatal respiratory distress syndrome (RDS) in preterm fetuses.

Methods: A prospective study conducted at Ain Shams University Maternity Hospital, Egypt from May 2015 to July 2017: 80 eligible women diagnosed with preterm labor were recruited at 32-36 weeks' gestation. Before delivery, three-dimensional ultrasound was used to estimate FLV using virtual organ computer-aided analysis (VOCAL), while PA-RI was measured by Doppler ultrasonography.

Results: A total of 80 women were examined. Thirty-seven (46%) of the newborns developed neonatal RDS. FLV was significantly lower in neonates who developed RDS (p = .04), whereas PARI was significantly higher in those who did not (p = .02). Cut-off values of FLV ≤27.2 cm³ and PARI ≥0.77 predicted the subsequent development of RDS. Combining both cut-offs generated a more sensitive and specific methodical approach for the prediction of RDS (sensitivity 100%, specificity 88.5%).

Conclusion: Measurement of FLV or PA-RI can predict RDS in preterm fetuses. Combined use of both measures bolstered their predictive significance.

Keywords: Fetal lung volume; Pulmonary Artery Resistance Index; VOCAL; neonatal respiratory distress syndrome.