Three-dimensional sonographic assessment of fetal behavior in the early second trimester of pregnancy

To evaluate the fetal behavior pattern in the early second trimester of pregnancy by use of specially developed abdominal dynamic three-dimensional sonography.

Dynamic three-dimensional sonographic examinations were performed on 11 healthy pregnant women at 14 to 18 weeks of gestation. This imaging system provided continuous three-dimensional sonographic images every 1 to 2 seconds. Fetal movements were recorded continuously for 60 minutes in each fetus. The rate of occurrence of head, mouth, arm, trunk, and leg movements was evaluated. All fetal behavioral patterns were observed during the period studied.

The active phase (time with fetal movements) was 59.4%, and the resting phase was 40.6%. The most active fetal behavior pattern was an arm movement, whereas the least was a mouth movement. Moreover, each fetal movement was synchronized and harmonized with other fetal movements (a few movement patterns were found to be generated simultaneously).

Dynamic three-dimensional sonography provides a novel means for evaluation of fetal behavior in the early second trimester of pregnancy. These results suggest that dynamic three-dimensional sonography may be an important modality in future early fetal behavior research and in evaluation of early fetal well-being.