Fetal adrenal gland volume at gestational age of 28–32 weeks for preterm birth prediction

Background: Preterm birth is the most common complication among pregnant women. Data collected by the World Health Organization found that worldwide preterm birth rates totaled 15-18%. As a result, newborn development is impaired, while perinatal morbidity and mortality increased. The process of spontaneous preterm birth is multifactorial. The published data showed the activation of the fetal hypothalamic-pituitary-adrenal axis is the one process during parturition. This theory guides the hypothesis that investigating the fetal adrenal gland may lead to discovering a tool to predict preterm birth in asymptomatic pregnant women. Methods: From February 2021 to October 2021, we recruited singleton pregnant women with gestational ages between 28 and 32 weeks who came for antenatal care at Phramongkutklao Hospital, Bangkok, Thailand. The measurements were obtained to calculate the total adrenal gland volume and fetal adrenal gland volume. All pregnant women were followed up until delivery. Receiver operating characteristic analysis was performed for preterm birth prediction to detect the best cut off value using the corrected fetal adrenal gland volume. Results: Altogether, 102 asymptomatic pregnant women were enrolled. The rate of preterm birth was 13.73% in this study. The ROC curve showed that the best cut off value using cFAGV was ≤18.11 mm 3 /kg (78.57% sensitivity, 45.45% specificity) for preterm birth prediction among asymptomatic pregnant women. Conclusions: Two-dimensional ultrasonographic measurements of corrected fetal adrenal gland volume in asymptomatic pregnant women at 28–32 weeks of gestation proved an unsuitable method for preterm birth prediction.