Fetal adrenal gland biometry as a prediction tool in labor induction.

Due to previous evidence showing that fetal adrenal gland parameters can serve as predictors of delivery in women with preterm uterine contractions, the objective of this study was to assess the association between fetal adrenal length and width to success of induction of labor. This prospective study was conducted in the delivery room of Carmel Medical Center, Haifa, Israel, during the years 2019-2021. Inclusion criteria were women with cervical Bishop score < 6, assigned to induction of labor due to various medical indications. Prior to induction of labor, sonography was performed for fetal adrenal length and width parameters, while adrenal volume was calculated using the formula of height*width/2. The induction was performed by vaginal Dinoprostone insert, or by double balloon catheter. Of 94 participants, successful induction of labor was achieved in 66 (70.2%). No significant differences were noted in fetal adrenal parameters between successful vs. failed induction: length 2.4±0. vs. 2.5±0.5 cm, width 1.0±0.5 vs. 1.2±0.4 cm, volume 1.3±0.7 vs. 1.5±0.6cm2, respectively. Using logistic regression analysis, a significant association was noted between successful induction of labor to higher maternal age and parity, as well as lower body mass index. An association was noted between fetal adrenal length and estimated fetal weight (Spearman's correlation coefficient 0.315, p=0.002). According to our results, fetal adrenal gland biometry was inefficient in predicting successful labor induction. Further larger-scaled studies should further explore this issue.