The value of repeated evaluation after initial failed nuchal translucency measurement

Area of Science:

• Prenatal screening
• Maternal-fetal medicine
• Diagnostic imaging

Background:

• Nuchal translucency (NT) measurement is a key component of first-trimester combined screening for fetal aneuploidy.
• Initial NT measurement failures can occur, potentially impacting screening effectiveness.
• Optimizing NT measurement success is crucial for accurate prenatal risk assessment.

Purpose of the Study:

• To evaluate the clinical utility of reattempting nuchal translucency (NT) measurements following an initial failed attempt.
• To determine if repeat NT measurements improve the overall success rate and diagnostic yield of aneuploidy screening.

Main Methods:

• A retrospective analysis of NT measurements performed by certified sonographers over 18 months.
• Categorization of women into 'desiring' screening, 'eligible' for screening, and 'defaulters' based on follow-up adherence.
• Offering reexamination for NT measurement if initially unobtainable in eligible patients with appropriate crown-rump length.

Main Results:

• Initial NT measurement success rates were 73.3% for all desiring screening and 80.0% for eligible women.
• Composite success rates significantly increased with up to three visits compared to a single visit (e.g., 84.8% vs. single visit for desiring screening).
• Repeat measurements detected an additional 16.6% of aneuploidies with similar screen-positive rates (10.4% vs. 11.0% for 1 vs. up to 3 visits).

Conclusions:

• Reattempting NT measurements substantially enhances the overall success rate of obtaining this crucial biometric data.
• This approach leads to the detection of additional aneuploidies without compromising the specificity of the screening program.
• Offering repeat NT measurements is a valuable strategy to improve the efficacy of first-trimester aneuploidy screening.