Table 1.

Classification proposed by Bettocchi in 2016 that recognizes four types of cervical stenosis depending on the structure or structures affected (ECO, cervical canal, ICO) [3]

Type	Structure affected
I	ECO stenosis
II	Cervical canal and ICO stenosis
III	ICO stenosis
IV	ECO and ICO stenosis

ECO external cervical os, ICO internal cervical os