LAUSR

Abstract The aim of this study was to create nomograms of the whole foetal adrenal gland and the foetal zone at 16–24 weeks of gestation in the Thai population, as well as to evaluate the relationships between the gestational age and the whole foetal adrenal gland and the foetal zone. Transabdominal measurement of the whole foetal adrenal gland and adrenal foetal zone were added to the routine biometric measurements at 16–24 weeks of gestation of singleton low-risk pregnancies. A total of 189 measurements were used for analysis. A linear correlation was observed between gestational age and the length, width and depth of the whole foetal adrenal gland at 16–24 weeks of gestation. A linear correlation was also found between gestational age and the length, width and depth of the foetal zone at 16–24 weeks of gestation. This study shows the linear growth of the foetal adrenal gland and foetal zone from 16–24 weeks of gestation. These reference values may be helpful in detecting abnormal growth of foetal adrenal gland or any abnormalities of the foetal adrenal gland. Impact Statement What is already known on this subject: Foetal adrenal glands play a pivotal role, mainly through steroidogenesis, in the regulation of the intrauterine homeostasis, and in foetal development and maturation. There is evidence to support that the foetus may be in control of the timing of its own birth by activating its hypothalamic-pituitary-adrenal axis to increase the production of dehydroepiandrosterone-sulphate to predominately induce the enlargement of the central foetal zone. What the results of this study add: This study shows the nomograms of the foetal adrenal gland and foetal zone from 16–24 weeks of gestation and the linear growth of the foetal adrenal gland and foetal zone from 16–24 weeks of gestation. What are the implications of these findings for clinical practice and/or further research:These reference values may be helpful in detecting abnormal growth of foetal adrenal gland or any abnormalities of the foetal adrenal gland.