Evaluating fetal lung development at various gestational weeks using two-dimensional shear wave elastography

Background: Noninvasive evaluation of fetal lung development is a critical area of study. Two-dimensional shear-wave elastography (2D-SWE) provides valuable insights into tissue stiffness, potentially correlating with different stages of lung development. This study aims to explore the potential of the 2D-SWE technique for assessing the maturity of fetal lung development. Methods: This prospective cohort study included pregnant women undergoing routine antenatal ultrasound examinations at the Second Affiliated Hospital of Fujian Medical University and Quanzhou Women's and Children's Hospital from September 2022 to September 2023. The study consecutively recruited 300 pregnant women with normal pregnancies and 15 who opted for induced labor. Among those with normal pregnancies, the study assessed the differences in fetal pulmonary and hepatic elasticity measurements across different gestational weeks (GW) using one-way analysis of variance (ANOVA). Furthermore, regression analyses using linear, quadratic, and cubic equations were conducted to investigate the relationship between fetal parameters and GW. For those who opted for induced labor, elasticity measurements were taken before induction, and fetal lung tissue specimens were collected for post-induction observation. Results: Fetal lung and liver elasticity values, along with the lung-to-liver elasticity ratio (LLE ratio), showed significant variations across different GW (P<0.05). Specifically, fetal lung elasticity values initially increased and then decreased as GW advanced (R2=0.41). Liver elasticity values continuously increased throughout GW, though the rate of increase diminished during the prenatal period (R2=0.37). The LLE ratio values increased and then decreased over GW, fluctuating overall between 0.8 and 0.9 (R2=0.14). A 71.4% concordance was observed between the predicted stage of lung development, based on lung elasticity values, and the histological stage of lung development in the induced fetuses. Conclusions: 2D-SWE can depict the maturation of fetal lung development at various stages.