Does the presence of a funnel increase the risk of adverse perinatal outcome in a patient with a short cervix?

The disruption of the internal os, as documented by funneling, is a significant risk factor for adverse perinatal outcome (ie, preterm labor, chorioamnionitis, abruption, rupture of the membranes, and serious neonatal morbidity and mortality). Cervical funneling is best measured as a categorical variable (present or absent).