Risk factors Most women with cervical insufficiency do not have known risk factors; however, the following risk factors have been identified: Multiple gestation Congenital disorders of collagen synthesis (eg, Ehlers-Danlos syndrome) Prior cone biopsy (particularly when ≥ 1.7 to 2.0 cm of the cervix was removed) or trachelectomy Prior deep cervical lacerations (usually secondary to vaginal or cesarean delivery) Prior excessive or rapid dilation with instruments (now uncommon) Müllerian duct defects (eg, bicornuate or septate uterus) ≥ 2 prior fetal losses during the 2nd trimester Recurrence Overall risk of recurrence of fetal loss due to cervical insufficiency is probably ≤ 30%, leading to the question of how large a role fixed structural abnormalities have.