OP08.11: Uterine artery pulsatility index assessment < 11 weeks of gestation: a prospective study

Abstract

Objectives: The fetal adrenal gland receives rising awareness as a predictor of spontaneous preterm birth. As previous studies focused on cross-sectional assessments, the aim of the present study was to provide longitudinal assessments of the fetal adrenal gland in a low risk population with an additional focus on growth-trajectories in fetuses born preterm. Methods: Analyses were based on data from a population-based low-risk prospective pregnancy cohort situated in Hamburg, Germany. Fetal adrenal gland was assessed via transabdominal ultrasound at gestational weeks (gw) 24-26, 28-30, and 34-36. Longitudinal trajectories of the total adrenal gland and the adrenal mark (so called fetal zone) as well as ratio of fetal zone width/ total adrenal gland widths (w/W) were analysed using repeated measurements ANOVA. To compare trajectories of the ratio w/W for fetuses preterm and term as well as women with and without clinical signs of preterm labour we additionally used the propensity score method. Results: Regarding total adrenal gland, longitudinal trajectories indicated a statistically significant increase for adrenal length, width, and volume (p < 0.0001) for those women with available measures at all three timepoints (n=386). Likewise, the fetal zone width increased over the course of pregnancy (p < 0.0001), while the ratio w/W decreased (p < 0.0001) (n= 329). Comparing the trajectories of the ratio w/W in fetuses born preterm (n=11) with propensity-score matched term born fetuses (n=22), a decrease between gw 24-26 and 28-30 was observed in both groups, which continued to decrease for the term born fetuses. However, in preterm born fetuses, the ratio increased above the term born values at gw 34-36. Conclusions: Our study provides longitudinal growth data on the fetal adrenal gland and supports the hypothesis that fetal zone enlargement is associated with preterm birth which could play an important role in risk-prediction. OP08.11 Uterine artery pulsatility index assessment < 11 weeks of gestation: a prospective study

B‐flow/spatiotemporal image correlation M‐mode: novel ultrasound method that detects decrease in spiral artery luminal diameter in first trimester in primate model of impaired spiral artery remodeling

“…However, an in-vivo assessment tool that can reliably quantify impaired SAR has not been developed. Although uterine artery flow resistance is currently used as a proxy marker for impaired placentation, its value in the first and second trimesters as a standalone test is limited [4][5][6] . Histological studies show clearly that extensively remodeled spiral arteries have a thin wall that accommodates increased blood flow, whereas poorly remodeled vessels retain a thickened wall and narrow lumen 7 .…”