Definition - What does Funneling Cervix mean?
A funneling cervix refers to a cervix that has changed its shape from a normal cylindrical-like structure to a funnel (either U or V shape) due to a widening of the internal opening of the cervix (called the internal os) and a reduction of the cervical length. A U-shaped funnel is associated with an increased risk of premature delivery or miscarriage.
FertilitySmarts explains Funneling Cervix
A funneling cervix is common in women with a prior spontaneous premature birth and short cervix. It is a sign of premature ripening of the cervix, also called cervical incompetence, a condition in which the cervix begins to widen and open too early during pregnancy before reaching term. The cervix needs to be long and strong enough to put up with the pressure of the growing baby inside the uterus.
In contrast, a wide and short cervix is weak and thus no longer capable of holding the growing baby, either leading to premature delivery or to a loss of pregnancy.
When cervical funneling occurs, the cervix changes its shape from a long and closed T-shaped organ to a Y-shaped, then V-shaped structure, later evolving into a U-shaped funnel as seen on an ultrasound. In such cases, placing a cervical cerclage or a stitch to close the cervix appears to provide pronounced benefits such as halting the funneling from worsening and preventing miscarriage or delaying the delivery. More surprisingly, these benefits increase as the cervical length decreases, i.e. contrary to what one would expect, it’s even easier to stitch a late-stage U-shaped funnel than the funnel at its early stages and hence prevent unnecessary complications.