The dilator may penetrate the cervical wall causing a perforation. It is also possible that the recess is interpreted as a fundus of an very small uterus. In that case the doctor may do a cervical curettage obtaining no tissue at all. If he assumes that the patient was not pregnant she will go home with an intact pregnancy. A similar problem arises when the internal ostium is obliterated by an old infection.
Cervical surgery can produce great problems.
Even simple cauterisation may make it almost impossible to flnd the external ostium. The problems are even greater after conisation and partial amputation of the cervix. If in these conditions the ostium is found it may be very difficult to enter it with an instrument so that dilation is impossible. For such cases a set of very thin dilators must be available. Once the ostium is opened dilation is generally no more difficult than in a normal cervix.