What is incompetent cervix?

Opening up too early. The cervix normally has a very small opening--the os--even during pregnancy. It should remain so until close to delivery at which time passage of the baby through the os is needed. Thus, close to birth time, the cervix begins to dilate from about <1cm to 10. If dilating too early (incompetent), there is risk of preterm delivery, hence concerning for incompetent cervix. Hope that helps. Good luck.
Bad news. Cervical incompetence is diagnosed when painless dilatation occurs at any gestational age. This frequently leads to pregnancy loss or preterm birth. All future pregnancies are then high risk and could benefit from Progesterone and cerclage prophylaxis as well as activity modification.