Can Thalamic Echogenicity by Ultrasound Be Used as a Predictor of Fetal Lung Maturity?

Aim: The present study aimed to evaluate using thalamic echogenicity by ultrasound as a predictor of fetal lung maturity in comparison with other ultrasound markers. Methods: This was a prospective study performed in Ain shams Maternity Hospital, Cairo, Egypt from August, 2020 until April 2021. Two hundred and thirty-eight pregnant women (36 to 40 weeks of gestation) who were admitted for elective cesarean section were recruited. An obstetric ultrasound scan was done at the same day of their elective cesarean section to evaluate echogenicity of the thalamus, to measure presence of ossification centers of distal femur epiphysis (DFE) and proximal tibia epiphysis (PTE), to measure biparietal diameter, to detect placental changes and amniotic fluid vernix. The outcome measures were APGAR scores at 1 minute and 5 minutes, admission to neonatal intensive care unit, duration of hospitalization and signs of respiratory distress syndrome (RDS). Results: The presence of echogenic thalamus as a sign of fetal lung maturity had a specificity of 77.2% which was lower than specificity of presence of PTE (90.4%) and measurement of BPD (82.6%). Diagnostic accuracy was 77.3% which was also lower than PTE (90.8%) and BPD (81.5%), respectively. Sensitivity was 78.9% which was lower than PTE (99.5%) and BPD (82.6%), respectively. Negative predictive value for thalamic echogenicity, PTE and DFE were 97.7%, 99.5% and 99.2%, respectively. Conclusion: Evaluation of echogenic thalamus could be an accurate method to predict fetal lung maturity. However, further studies are required to strengthen such idea.