NCT07165743

Evaluation of Fetal Bladder Emptying During the 11-14 Weeks' Ultrasound Examination as a Negative Predictive Marker for Chromosomal Abnormalities

Negative Predictive Value of Rapid Emptying of the Fetal Bladder (≤40 Min and Post-void ≤2 mm) on Major Chromosome Aneuploidies at 11-14 Gestational Weeks: A Prospective Diagnostic Accuracy Study

• Status: Active Not Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 270 (estimated)
• Sponsor: Haseki Training and Research Hospital · Academic / Other
• Sex: Female
• Age: 18 Years – 45 Years
• Healthy volunteers: Accepted

Summary

Template-Based Brief Summary (Sağlık Profesyonelleri İçin) Study Title: The Negative Predictive Value of First-Trimester Fetal Bladder "Rapid Emptying" (≤40 minutes and post-void ≤2 mm) for Major Chromosomal Aneuploidies: A Prospective Diagnostic Accuracy Study. Purpose: To evaluate whether the dynamic phenotype of rapid bladder emptying at 11-14 weeks reduces the likelihood of major chromosomal abnormalities (particularly Trisomy 21) compared to fetuses without this phenotype. Design: Single-center, prospective observational cohort. Population: 270 singleton pregnancies between 11+0 and 14+0 weeks. Procedures: Real-time sagittal ultrasound observation for 40 minutes. Documentation of bladder emptying time and post-void longitudinal bladder diameter. Concurrent measurement of CRL, NT, ductus venosus waveform. Gold standard confirmation with cfDNA or invasive karyotyping in high-risk cases. Primary Endpoint: Negative predictive value (NPV), ROC-AUC, sensitivity/specificity for aneuploidy detection. Secondary Endpoints: Rate of invasive testing, performance in combined models with cfDNA and biophysical markers, Net Reclassification Index. Duration: 5 months (08/2025 - 01/2026). Potential Impact: If validated, the rapid emptying phenotype may serve as a low-risk marker, reduce unnecessary invasive procedures, and refine first-trimester screening algorithms.

Conditions

• Chromosomal Aneuploidies (e.g., Trisomy 21, Trisomy 18, Trisomy 13); Prenatal Screening Accuracy

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	40-Minute Real-Time First-Trimester Ultrasonography	A one-time midsagittal ultrasound performed between 11 +0 and 14 +0 weeks. Bladder emptying time and post-void longitudinal bladder diameter are recorded. No invasive procedures are performed.

Timeline

• Start date: 2025-08-28
• Primary completion: 2025-10-31
• Completion: 2026-01-30
• First posted: 2025-09-10
• Last updated: 2025-09-10

Locations

1 site across 1 country: Turkey (Türkiye)