Improving precision of second-trimester biometry

To utilise image score-based criteria for second-trimester fetal biometry as an educational tool to improve biometry quality.

Five sonographers regularly performing obstetric ultrasound examinations were recruited for this study. Biometry images were collected from fifteen second-trimester examinations for each sonographer prior to participating in a biometry education session, and another set of biometry images were collected from fifteen second-trimester examinations following the education session. The education session was a one-hour presentation that explained image score-based criteria to evaluate and grade the quality of the bi-parietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL) and humeral length (HL) biometry parameters. Each of the five sonographers performed a total of 30 examinations (15 pre- and 15 post-education session). From these examinations, a total of 150 images were collected for each biometry parameter (75 pre- and 75 post-education). A total of 600 biometry images were evaluated. Images from both the pre- and post-education session were assessed by an obstetrician sonologist using the same image score-based criteria. Pre- and post-image scores were compared using paired t-tests.

Improvement in the mean image scores for all biometry parameters was observed after the education session. The difference between pre- and post-education image quality scores was significant for the AC (P = 0.01), FL (P = 0.002) and for the overall score (P = 0.001).

Implementing an image score-based criteria evaluation technique is a simple and useful method to improve fetal biometry precision.