Implementation and Performance of First-Trimester Referral Ultrasound Scan Following the Introduction of National...

Area of Science:

• Prenatal diagnostics
• Fetal medicine
• Medical imaging

Background:

• National guidelines for first-trimester ultrasound (US) referral scans were published in Italy.
• Fetal Medicine units implemented these guidelines to assess fetal anatomy in early pregnancy.
• Cases were referred for expert assessment due to increased risk for structural anomalies.

Purpose of the Study:

• To evaluate the implementation of national first-trimester referral US guidelines in Italy.
• To assess the diagnostic performance of first-trimester US in identifying fetal anomalies.
• To determine the agreement between first and second-trimester referral scans.

Main Methods:

• A multicenter, retrospective study included singleton pregnancies referred for specialized US between 11 and 14 weeks' gestation.
• Referral criteria included nuchal translucency (NT) ≥ 3.5 mm or suspected anomaly.
• Diagnostic accuracy was compared between first-trimester US and follow-up scans at 14-16 or 19-21 weeks.

Main Results:

• 322 out of 344 (93.6%) cases underwent timely first-trimester referral US.
• Agreement between 11-14 week and 19-21 week scans was 85.3% (Sensitivity 82.0%, Specificity 88.0%).
• Agreement between early scans and 14-16 week scans was 91.3% (Sensitivity 90.7%, Specificity 92.1%).

Conclusions:

• The study confirms successful implementation of national first-trimester referral US guidelines in Italy.
• First-trimester fetal anatomy assessment by experienced operators is feasible.
• High diagnostic accuracy in the first trimester enables early detection of structural fetal anomalies.