Fetal anatomic survey using three-dimensional ultrasound in conjunction with first-trimester nuchal translucency screening.

OBJECTIVE

To determine the visualization rates of fetal anatomic structures by three-dimensional ultrasound (3DUS) at 12-13 weeks of gestation.

STUDY

DESIGN

This was a prospective observational study of women presenting for nuchal translucency ultrasound. Five 3D volumes of the fetus were acquired transabdominally. Two investigators independently reviewed the stored volumes offline following a standardized protocol.

RESULTS

One hundred singleton fetuses were examined. The mean time for 3D volumes acquisition was 4.8 min; and for 3D review 17 min. Anatomic structures were seen as follows: cranium, lateral cerebral ventricles and abdominal wall 100%; stomach, vertebrae, upper and lower limbs >or= 94%; face 71%, bladder 58%, both kidneys 39%, skin overlying spine 26% and heart 18%. Agreement between two observers ranged from 100% (for head, abdominal wall and lower limbs) to 43% (for visualization of skin overlying spine). A complete basic anatomic survey was achieved in 11.4% of the 12-week fetuses and 33.3% of the 13-week fetuses (p-value = 0.038).

CONCLUSIONS

First-trimester transabdominal 3DUS was adequate for assessment of the head, abdominal wall, stomach, limbs and vertebral alignment. It was less effective for evaluating the heart and intactness of the skin over the spine.