Aim: To perform a systematic review to assess the accuracy of first-trimester ultrasound (US) in the diagnoses of major structural malformations in chromosomally normal fetuses.
Methods: References were obtained from the MEDLINE database, without time range limitations. For each, the risk of bias was evaluated and the important data were extracted. Only studies that used first-trimester US to diagnose major structural malformations were included. We evaluated the sensitivity of US over a low-risk unselected population of pregnant women carrying euploid fetuses.
Results: A total of 19 studies were included, contributing to 126,937 fetuses and 1399 major malformations. The prevalence of lethal and severe malformations obtained was 1.2% [95% confidence interval (CI), 1.0-1.4]. Both averaged and pooled sensitivity, 50.0% (95% CI 44.1-55.9) and 45.2%, respectively, presented a moderate value for first-trimester US in the detection of structural malformations.
Conclusion: Based on our analysis of the data, the average sensitivity of first-trimester US to detect structural malformations was 50%. It is our conviction that US has the potential to evolve in this role by exploiting the natural history of malformations and the development of US techniques.