Methodology for Using 3-Dimensional Sonography to Measure Fetal Adrenal Gland Volumes in Pregnant Women With and Without Early Life Stress.

ABSTRACT

Fetal adrenal gland volumes on 3-dimensional sonography have been studied as potential predictors of preterm birth. However, no consistent methodology has been published. This article describes the methodology used in a study that is evaluating the effects of maternal early life stress on fetal adrenal growth to allow other researchers to compare methodologies across studies. Fetal volumetric data were obtained in 36 women at 20 to 22 and 28 to 30 weeks' gestation. Two independent examiners measured multiple images of a single fetal adrenal gland from each sonogram. Intra- and inter-rater consistency was examined. In addition, fetal adrenal volumes between male and female fetuses were reported. The intra- and inter-rater reliability was satisfactory when the mean of 3 measurements from each rater was used. At 20 weeks' gestation, male fetuses had larger average adjusted adrenal volumes than female fetuses (mean, 0.897 versus 0.638; P = .004). At 28 weeks' gestation, the fetal weight was more influential in determining values for adjusted fetal adrenal volume (0.672 for male fetuses versus 0.526 for female fetuses; P = .034). This article presents a methodology for assessing fetal adrenal volume using 3-dimensional sonography that can be used by other researchers to provide more consistency across studies.