Invasive cervical cancer is the most common form of malignancy in pregnant women. The incidence of carcinoma in situ—generally detected through an abnormal Pap smear—is increasing along with the median reproductive age in women who reside in industrialized countries. The threat that CIS will progress to invasive cervical cancer is a particular concern in relatively older women. In an effort to clarify the problem of whether cone biopsy should be done during pregnancy, the course of disease was followed prospectively in 83 pregnant women seen in the years 1996–2004 in whom a colposcopic-guided punch biopsy of the cervix disclosed squamous-cell CIS. The state of the cervix was estimated every 8 weeks by a Pap smear and colposcopy up to 36 weeks' gestation, and again 6 to 8 weeks after delivery. About 40% of affected women were seen in the first trimester, 41% in the second, and the rest in the third trimester.
Of 68 women evaluated before pregnancy, 25 had low-grade, and 5 high-grade lesions. In more than 90% of cases, the colposcopic impression of CIS correlated with the biopsy findings. A total of 77 patients were followed up for a median of 140 days before delivery. The rate of postpartum regression was 34%. Two patients received a diagnosis of microinvasive cervical cancer from the findings at postpartum cone biopsy. CIS persisted in 63% of cases. The course of CIS did not depend on the route of delivery. Both patients with microinvasive carcinoma had primary cesarean delivery, and were free of disease when evaluated after 24 and 38 months, respectively. Eight women followed up for a median of 38 months again had suspect Pap smear findings, and all of them remained high-risk positive for human papillomavirus (HPV).
These findings support a policy of observation for women in whom cervical CIS is found during pregnancy. HPV testing may be helpful for detecting recurrent dysplasia. A negative colposcopic-guided biopsy should exclude invasive disease. If invasion is suspected, operative delivery should be considered.