INTRODUCTION
Preterm birth (PTB) is a major cause of neonatal morbidity and
mortality, affecting 10% of births worldwide 1, 2.
Long-term pulmonary or neurodevelopmental disabilities and the mortality
risk of prematurity extend beyond the neonatal ICU, even into childhood
and adolescence 3-5. The majority of births before
term are spontaneous due to preterm labor (PTL), preterm prelabor
rupture of membranes (PPROM), and cervical insufficiency, but the
etiology is often unknown 6. Shortened cervical length
(CL) is the target of several preventative interventions, such as
progesterone supplementation and cervical cerclage, both of which have
been shown to reduce PTB risk 7, 8. However,
sonographic CL has variable sensitivity for screening, and its
predictive value in the general obstetric population remains suboptimal7, 9, 10. The character of the cervical canal itself,
specifically the cervical gland area (CGA), has been proposed as another
useful reflection of cervical function 11-13.
The CGA is a hyper- or hypoechoic zone lining the cervical canal,
distinct in echotexture from the cervical stroma, and corresponds to the
histologic endocervical crypts (Figure 1) 14. This
glandular tissue is responsible for maintaining the collagen, elastin,
and proteoglycans that help impart the firm cervical consistency
necessary to sustain a pregnancy, as well as producing endocervical
mucus to help prevent ascending genital infections15-17. Normal and preterm cervical ripening is thought
to be related to collagenolysis and changes in cervical water content
that disrupt the structural integrity of these glands, resulting in
softening, effacement, and insufficiency. The collagenolysis involved in
cervical ripening may correspond to loss of a sonographically detectable
CGA 12, 18, 19. However, CGA is not a widely known
marker of cervical integrity in clinical practice. Exploring a
relationship between the CGA, CL, and PTB could potentially facilitate
beneficial interventions. The objective of our study is to
sonographically characterize the CGA and determine if its evaluation at
the time of routine CL screening can be useful for PTB prediction.