Chromosomal Aneuploidies (e.g., Trisomy 21, Trisomy 18, Trisomy 13); Prenatal Screening Accuracy
Conditions
Keywords
First-trimester screening Chromosomal abnormalities Prenatal diagnosis Ultrasound Negative predictive value (NPV) Fetal bladder
Brief 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.
Interventions
DIAGNOSTIC_TEST40-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.
Sponsors
Haseki Training and Research Hospital
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Singleton, viable pregnancy between 11 + 0 and 14 + 0 gestational weeks (GA) * Maternal age 18 - 45 years at enrollment * Able to provide written informed consent
Exclusion criteria
* Multiple gestation (twins, higher order) * Major fetal structural anomaly detected at index scan * Known serious maternal comorbidity (e.g., insulin-dependent diabetes, uncontrolled hypertension, renal or autoimmune disease) * Participation in another interventional research study during the current pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Negative Predictive Value (NPV) of Rapid Fetal Bladder Emptying for Detecting Major Chromosomal Aneuploidy | From enrollment at 11 + 0 to 14 + 0 gestational weeks until definitive genetic result or delivery, whichever comes first (≈ 26 weeks). | Proportion of fetuses with the rapid-emptying phenotype (≤ 40-minute complete emptying + post-void longitudinal bladder diameter ≤ 2 mm) who are subsequently confirmed not to have a major chromosomal aneuploidy (Trisomy 21, 18, or 13) by cfDNA, invasive karyotype, or postnatal testing. |
Countries
Turkey (Türkiye)
Outcome results
None listed