Cervical weakness and infection have long been regarded as major causes of preterm birth. Cervical cerclage has been used extensively to reduce the risk of preterm birth arising as a result of cervical weakness, but increasing evidence suggests that the cervix plays more than just a mechanical role. Immunological function of the cervix and mucus plug is thought to be important in minimising the ingress of microbes, which can lead to chorioamnionitis and rupture of the amniotic membranes. In this review, we examine the background of traditional cervical cerclage and introduce the concept of the occlusion suture and its potential benefit in reducing the risk of recurrent preterm prelabour rupture of membranes.