Society for Maternal-Fetal Medicine: Better ways to predict preterm birth

April 1, 2010

Researchers from the University of Maryland and Yale University demonstrated that a 2-dimensional ultrasound measurement of the fetal zone of the adrenal gland is as accurate as predicting pre-term birth as the less available 3-dimensional ultrasound measurement of fetal adrenal gland volume.

Researchers from the University of Maryland and Yale University demonstrated that a 2-dimensional (2D) ultrasound measurement of the fetal zone of the adrenal gland is as accurate at predicting preterm birth as the less-available 3-dimensional (3D) ultrasound measurement of fetal adrenal gland volume (AGV) and that both are more accurate than the traditional measurement of cervical length (CL), which has a high false-positive rate.

Ozhan Turan, MD, and colleagues enrolled 62 women with singleton pregnancies who had preterm labor symptoms between 23 and 37 weeks' gestation. The women received ultrasound measurement of CL and fetal adrenal gland dimension. Using 3D ultrasound with VOCAL cAGV (fetal AGV/estimated fetal weight), 2D depth of the whole-gland (D) and fetal zone (d) were measured. The researchers calculated d/D ratio as an index of fetal zone enlargement and compared cAGV, d/D, and CL in terms of predicting birth within 7 days.

Measurement-to-delivery interval correlated with cAGV and d/D (r=–.32, P=.011, and r=–.47, P=.001, respectively) but not with CL (P=.83). The receiver-operating-characteristic area under the curve was significantly greater for cAGV and d/D than for CL (0.82, 0.91, 0.59; P<.01 and P<.001, respectively).