Longitudinal adrenal gland measurements and growth trajectories as risk markers for late preterm delivery

Abstract Background The fetal adrenal gland receives rising awareness as a predictor of spontaneous preterm birth. We hereby provide longitudinal growth assessments of the fetal adrenal gland in a low risk population with an additional focus on trajectories in fetuses born preterm. Methods Fetal adrenal gland was assessed via transabdominal ultrasound at gestational weeks (gw) 24–26, 28–30, and 34–36 in a low-risk pregnancy cohort. Longitudinal trajectories of the total gland and the mark (so called fetal zone) as well as ratio of fetal zone width/ total widths (w/W) were analyzed using repeated ANOVA analyses. To compare trajectories of the ratio w/W for preterm and term fetuses respectively, as well as women with and without clinical signs of preterm labor, the propensity score method was applied. Results Fetal zone width increased over the course of pregnancy (p