0.52.# Cervical length < 18 mm# Funnel length > 9 mm.# Funnel width > 6 mm.o Diagnosis in non - pregnant state:1) Passage without resistance and pain of No. 8 Hegarrs dilator.2) Cervicogram : shows funnel shaped cervix.3) Intracervical balloon studies: Pass a balloon (e.g. Foley's) into cervical canal and inflate it with a radio - opaque dye and then take x - rays after applying due traction. Pear shaped shadow of balloon due to funneling of cervical canal indicates incompetent os.4) Traction studies : Pass foley's catheter through internal os of cervix and inflate it with 5 - 10 ml and apply traction. If traction of 600 gm or less is enough to pull out the bulb through the os, then the diagnosis is certain.5) Bromen papaine test : This dye selectively dilates the cervico - uterine junction. After injecting the dye (locally into the cervix and intramuscularly.">