Cervical Insufficiency

Historically, cervical insufficiency was defined as painless cervical dilatation which results in mid-trimester pregnancy loss when other causes have been excluded. This history-based definition requires the patient to experience pregnancy loss that too recurrent. More recently, the expanded definition of cervical insufficiency includes women who have a prior spontaneous preterm birth with sonographic evidence of cervical shortening (<25 mm) on transvaginal ultrasound [1].