Predicting Late-Term Pregnancy: The Role of Corrected Fetal Adrenal Gland Volume in Low-Risk Pregnants

Late-term pregnancy is commonly seen in obstetrics and is linked to adverse outcomes. Corrected fetal adrenal gland volume (cAGV) is an ultrasound marker that was used to predict preterm labor. The objective was to determine whether cAGV, in conjunction with other maternal risk factors, could predict late-term pregnancy among low-risk pregnant women in order to improve obstetric care. A prospective study recruited 177 low-risk primigravida women. Ultrasound-based cAGV was calculated for all participants at 37 weeks. Participants were followed until the day of delivery; accordingly, they were divided into two groups: Control group (137/177) delivered at term (37 + 0/7-40 + 6/7) weeks and late-term group (40/177) who delivered at (41 + 0/7-41 + 6/7) weeks. Maternal age, body mass index (BMI), and gestational age were collected for all participants alongside ultrasound data such as fetal biometry, gender, and estimated fetal weight. The participants' mean age was (27.32 ± 5.17) years. The cAGV was significantly lower among pregnant women who passed their due dates and was inversely correlated to the gestational age (r = - 0.6, P < 0.001). The cAGV exhibited a high probability of predicting late-term pregnancy (OR = 3.47; 95% CI = 1.37 to 8.79; P = 0.009). In contrast, maternal age, maternal BMI, and the presence of a male fetus did not demonstrate any significance as predictors. The cAGV cut-off value (≤ 277mm3/kg) predicted late-term pregnancy (P < 0.001) at a 77.5% sensitivity and 91.2% specificity. The cAGV can predict late-term pregnancy with good sensitivity and specificity. It is proposed as a promising tool for clinical use as non-invasive ultrasound obtained at no extra cost during routine 2-dimensional ultrasound examinations. More studies are warranted to explore further applications in improving feto-maternal outcomes among late-term pregnnat.