Cervical incompetence is when the cervix measures less than
High-Yield Explanation
Cervical incompetence diagnosis : History of repeated midtrimester painless cervical dilatation with escape of liquor amnii followed by painless expulsion of products of conception Passage number 6-8 Hegor dilator beyond internal os without resistance Absence of opening snap on withdrawal of Hegar dilator Hysterography showing funnel shaped shadow During pregnancy ,sonography showing sho cervix <25 mm. Speculum examination showing dilatation of internal os with herniation of membranes. Ref: Dutta Obs 9e pg 161.