Combination of three-dimensional ultrasound measurement of foetal adrenal gland enlargement and placental alpha microglobulin-1 for the prediction of the timing of delivery within seven days in women with threatened preterm labour and preterm labour

The aim of this study was to predict the timing of delivery within seven days in singleton pregnant women with threatened preterm labour and preterm labour by using a three-dimensional (3D) ultrasound measurement of foetal adrenal gland volume enlargement, a foetal zone enlargement and cervicovaginal placental alpha microglobulin-1 (PAMG-1) test. This prospective cohort study included singleton pregnant women at 22–36+6 weeks of gestation who presented with threatened preterm labour and with preterm labour. Transabdominal 3D ultrasound measurement of the whole foetal adrenal gland and of the foetal adrenal zone were performed. Qualitative cervicovaginal PAMG-1 detection was performed at the same time. One hundred and fifty-four pregnant women were included into the study. Eighty-four pregnant women had threatened preterm labour and seventy pregnant women had preterm labour. Twenty-nine pregnant women (18%) delivered within seven days. Use of foetal adrenal gland volume enlargement, foetal zone enlargement and the PAMG-1 test in combination increased sensitivity; if one parameter was positive, the sensitivity, specificity, positive predictive value and negative predictive value were 82.8%, 27.2%, 20.9% and 87.2%, respectively, in the prediction of the timing of delivery within seven days. The combination of foetal adrenal gland enlargement and PAMG-1 increased sensitivity for the prediction of the timing of delivery within seven days in pregnant women presenting with threatened preterm labour and preterm labour.Impact Statement What is already known on this subject? An increased foetal adrenal gland volume is significantly correlated with the risk of preterm birth. What do the results of this study add? The combination of a foetal adrenal gland enlargement and a placental alpha microglobulin-1 increased sensitivity for the prediction of the timing of delivery within seven days in pregnant women presenting with threatened preterm labour and preterm labour. What are the implications of these findings for clinical practice and/or further research? The combination of a foetal adrenal gland enlargement and placental alpha microglobulin-1 may be used for the prediction of the timing of delivery within seven days in pregnant women presenting with threatened preterm labour and with preterm labour