Defining the spatial relationships between eight anatomic planes in the 11+6 to 13+6 weeks fetus: a pilot study

Our study aims at investigating the spatial relationships between eight anatomic planes in the 11+6 to 13+6 weeks fetus.

This is a retrospective pilot study where three-dimensional and four-dimensional stored data sets were manipulated to retrieve eight anatomic planes starting from the midsagittal plane of the fetus. Standardization of volumes was performed at the level of the transverse abdominal circumference plane. Parallel shift was utilized and the spatial relationships between eight anatomic planes were established. The median and the range were calculated for each of the planes, and they were evaluated as a function of the fetal crown-rump length. P < 0.05 was considered statistically significant.

A total of 63 volume data sets were analyzed. The eight anatomic planes were found to adhere to normal distribution curves, and most of the planes were in a definable relationship to each other with statistically significant correlations.

To our knowledge, this is the first study to describe the possible spatial relationships between eight two-dimensional anatomic planes in the 11+6 to 13+6 weeks fetus, utilizing a standardized approach. Defining these spatial relationships may serve as the first step for the potential future development of automation software for fetal anatomic assessment at 11+6 to 13+6 weeks.