Accuracy of combined fetal lung volume and pulmonary artery doppler in predicting respiratory distress syndrome after elective cesarean section in diabetic pregnancies.

Summary

In 123 diabetic pregnancies undergoing elective cesarean section, lower fetal lung volume and higher pulmonary artery resistance index strongly predicted neonatal RDS. ROC analyses showed excellent performance for each metric and best accuracy when combined (AUC 0.981), with PA-RI achieving 100% sensitivity and NPV in this cohort.

Key Findings

• RDS incidence was 13.0% (16/123) among diabetic pregnancies undergoing elective cesarean.
• Affected neonates had lower median FLV (29.8 vs 38.2 cm³, p<0.001) and higher median PA-RI (0.88 vs 0.68, p<0.001).
• FLV ≤33.5 cm³: sensitivity 93.8%, specificity 87.9%, PPV 53.6%, NPV 99.0% (AUC 0.941).
• PA-RI >0.75: sensitivity 100%, specificity 90.7%, PPV 64.0%, NPV 100% (AUC 0.963).
• Combined FLV+PA-RI model achieved the highest accuracy (AUC 0.981) and correlated with RDS severity and NICU stay (FLV: −0.80/−0.77; PA-RI: +0.77/+0.75).

Clinical Implications

PA-RI and FLV can guide timing of delivery, antenatal corticosteroid administration, and NICU preparedness; high NPV supports safely avoiding unnecessary escalation when values are favorable.

Limitations

• Single-center with modest sample size limits generalizability
• Restricted to diabetic pregnancies undergoing elective cesarean; external validation needed

Future Directions

Validate FLV+PA-RI thresholds in multicenter, diverse obstetric populations; assess impact on management decisions and neonatal outcomes.