M. Guilleumes

Objective: To establish and assess the reproducibility of standardized echocardiographic nomenclature and the protocol for comprehensive evaluation of fetal aortic morphology. Methods: This was a prospective cohort study of fetuses with a normal three‐vessel branching pattern of the aortic arch, evaluated from 18–40 weeks' gestation at a single center between January 2024 and November 2024. Alongside standard two‐dimensional views, four‐dimensional spatiotemporal image correlation cardiac volumes were acquired to establish the correspondence between the longitudinal aortic‐arch view and the three‐vessel‐and‐trachea (3VT) view. A comprehensive nomenclature, based on clear anatomical landmarks, and stringent measurement protocol were defined for fetal aortic dimensions and angles measured in the left ventricular outflow tract (LVOT), the longitudinal aortic‐arch and the 3VT echocardiographic views. Measurements were performed independently by two observers, with a repeat analysis by a single observer, to assess intra‐ and interobserver reproducibility, respectively, using intraclass correlation coefficients (ICCs). Results: A total of 45 singleton fetuses with normal three‐vessel branching were randomly selected to comprise the study population. Parameters measured in the LVOT view demonstrated good‐to‐excellent intra‐ and interobserver reproducibility (ICC > 0.8), with excellent reproducibility observed for the sinotubular junction and mid‐ascending aorta diameters (except the interobserver reproducibility for mid‐ascending aorta diameter (ICC, 0.883 (95% CI, 0.739–0.945)), which was good). Good‐to‐excellent intra‐ and interobserver reproducibility (ICC, 0.8–0.9) was also demonstrated for longitudinal aortic‐arch diameters and distances between supra‐aortic vessels, whereas the ascending‐to‐descending aorta angle showed moderate intra‐ and interobserver reproducibility (ICC, 0.652 (95% CI, 0.435–0.798) and 0.593 (95% CI, 0.199–0.776), respectively). In the 3VT view, the standardized aortic diameters and the 3VT angle had good‐to‐excellent intraobserver reproducibility (ICC, 0.75–0.9). There was also good agreement between the aortic isthmus diameter in the longitudinal aortic‐arch view and the 3VT view (ICC, 0.870 (95% CI, 0.458–0.995); P < 0.001). No significant differences or systematic bias were found between observers. Conclusion: A standardized echocardiographic protocol with uniform nomenclature and anatomical landmarks would enable reliable and reproducible fetal aortic morphometry across multiple echocardiographic views, and would be a significant step towards harmonizing fetal aorta imaging, enabling meaningful comparisons across studies and promoting collaborative research. © 2026 International Society of Ultrasound in Obstetrics and Gynecology.

Objective: To evaluate whether fetuses exposed to threatened preterm labor (PTL) without intra‐amniotic infection or inflammation (IAI), who were born ≥ 34 weeks' gestation, show signs of cardiac remodeling and dysfunction at admission and 4 weeks after the episode of threatened PTL. Methods: This was a prospective cohort study conducted at two tertiary referral centers including pregnant patients admitted between September 2018 and April 2021. The study group comprised women with singleton pregnancies and intact membranes who were admitted with a diagnosis of PTL between 23 and 34 weeks' gestation. Pregnancies were eligible for inclusion if amniocentesis was performed at admission and ruled out the occurrence of IAI. Exclusion criteria included latency to delivery shorter than 4 weeks and delivery < 34 weeks. Fetal echocardiography was performed within 72 h after admission and was repeated at follow‐up 4 weeks later. A control group of singleton pregnancies without PTL or preterm prelabor rupture of membranes (PPROM), matched with the study group at a ratio of 1:1 by gestational age at ultrasound, was also evaluated. Fetal cardiac morphology and function were assessed using a standardized echocardiographic protocol, and compared between the two groups. Amniotic fluid troponin I and N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) concentrations were measured in the study group at the time at which amniocentesis was performed, and were compared with 20 amniotic fluid samples from the Clinic‐IDIBAPS Biobank that had been collected for indications other than PTL/PPROM or cardiac pathology. Results: A total of 32 fetuses exposed to threatened PTL (of which 84.4% were born at term) and 43 controls were compared. At admission, fetuses exposed to threatened PTL already showed signs of cardiac remodeling compared with controls, including a more globular cardiac shape (median global sphericity index, 1.17 vs 1.23; P = 0.012), an increased right atrial area‐to‐heart area ratio (median, 0.18 vs 0.16; P = 0.006) and early signs of diastolic dysfunction (median lower tricuspid E/A ratio, 0.65 vs 0.72; P = 0.027) and increased systolic function (median tricuspid annular plane systolic excursion, 6.5 vs 6.0 mm; P = 0.036). At admission, the threatened‐PTL group also showed significantly higher amniotic fluid troponin‐I levels (median, 1222.8 pg/mL vs 841.3 pg/mL; P = 0.026). Amniotic fluid NT‐proBNP was detectable in 25% of these cases, compared with none in the control group. At 4 weeks after the first ultrasound evaluation, in fetuses from mothers with threatened PTL, we observed that systolic function had normalized but cardiac remodeling persisted. These fetuses still exhibited a more globular cardiac shape (median global sphericity index, 1.16 vs 1.25; P = 0.036), and they now had a larger right ventricle (RV) (median RV area‐to‐heart area ratio, 0.26 vs 0.24; P = 0.037) without cardiomegaly. Diastolic function remained altered, with prolonged tricuspid inflow duration (median inflow time fraction, 0.39 vs 0.35; P = 0.001) and longer atrial contraction (median atrial time fraction, 0.23 vs 0.20; P = 0.039). Conclusions: Fetuses exposed to threatened PTL without IAI, who were born ≥ 34 weeks' gestation, exhibited signs of cardiac remodeling and subclinical diastolic dysfunction of the RV at admission that persisted for at least 4 weeks. Early identification of threatened PTL may provide opportunities to apply preventive strategies aimed at improving long‐term cardiovascular health. © 2026 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.