Pregnancy following conization of the cervix: complications related to cone size.

A retrospective study of 88 pregnancies occurring in 77 patients after cervical conization was undertaken to compare pregnancy outcome with cone size. Cone specimens were divided into two groups. Those measuring less than 2 cm in height or less than 4 cc in volume were considered to be "small cones" and those greater than 2 cm in height or 4 cc in volume were regarded as "large cones." The over-all normal term vaginal delivery rate was 46.6%, and was found to be inversely proportional to the size of the cone. The incidence of both spontaneous midtrimester abortion and prematurity increased in direct proportion to cone size. Cervical stenosis necessitating cesarean section was, however, noted to be a complication associated with small rather than large cones. It was concluded from this study that all postcone pregnancies should be regarded as high risk, preterm complications being particularly related to large cones.