The concept that a cervix could be inadequate or incompetent for retaining a normal pregnancy was publicized by Lash and Lash in 1950. It did not catch the fancy of the majority of obstetricians to any extent until the introduction of the relatively simple corrective procedure advocated by Shirodkar in 1955 and publicized by Barter et al. Since then there has been a constantly increasing number of reports discussing this problem. Incompetent cervical os is estimated to represent only a small percentage of all causes of fetal wastage …