Evaluation of the role of first-trimester obstetric ultrasound in the detection of major anomalies: a systematic review.
OBJECTIVE
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.


CONCLUSIONS
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.
Sílvia
S
Farraposo
Nuno
N
Montenegro
Alexandra
A
Matias
D000013:Congenital Abnormalities / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D016216:Ultrasonography, Prenatal