Fetus or newborn affected by incompetence of cervix uteri

**Definition:** Cervical incompetence refers to a weakness of the cervix and lower uterine segment, which can lead to recurrent second-trimester or early third-trimester loss of pregnancy due to an inability of the uterine cervix to retain a pregnancy until term. It is associated with a premature shortening of the cervix, dilatation, and opening of the cervical os during pregnancy. Ultrasound changes that suggest cervical incompetence include a cervical length < 1.5 cm, cervical width > 3 cm, and an expanded cervical canal > 8 mm.