During an 8-year period, 200 patients with biopsy-proved cervical intraepithelial neoplasia grade 3 (CIN3) of the cervix were evaluated serially both before and after birth with serial Cytobrush cytology, colposcopy, and biopsy. No patient underwent cervical conization, regardless of cytological or colposcopic findings. Ninety percent of patients had postpartum CIN3, 5% had CIN1, and 4.5% showed no evidence of dysplasia. One patient was found to have a stage IA2 invasive squamous cell carcinoma of the cervix on postpartum conization. CIN3 rarely regresses postpartum, but conization may be avoided even in the presence of unsatisfactory colposcopy, discrepancy between Papanicolaou smear and biopsy, or cytological findings consistent with early invasive cervical cancer.