Arguments in support of this process
have been provided by an autopsy study,
which demonstrated that neonates that
delivered in the setting of idiopathic PTB
had significantly higher adrenal gland
weight than those that delivered secondary
to fetal/maternal hemorrhage.7 In a
prior study, we were able to show that the
3-dimensional (3D) ultrasound measurement
of fetal adrenal gland volume
(AGV) allows prenatal identification ofthis process.8 In that study the increased
volume of the whole fetal adrenal gland
significantly correlated with the risk for
PTB.
However, whereas 3D ultrasound
studies of the AGV may provide valuable
insight in studying the pathophysiology
of fetal adaptation to intrauterine stressors
and fetal contribution to the preterm
labor process, they are technically
challenging and have not achieved generalized
clinical application. In addition,
this method evaluates the whole gland
rather than the physiologically relevant
fetal zone. In addition, a comparative
analysis of the predictive value ofAGCvs
CL has not yet been performed. Herein
we sought to test the hypothesis that ultrasound
evaluation of fetal adrenal
gland volume and the central fetal zone
size are predictive of PTB better than cervical
length measurement.