Natural history of cervical intraepithelial neoplasia during pregnancy

Objective. It is uncertain whether pregnancy influences the natural history of cervical intraepithelial neoplasia (CIN). Our aim was to evaluate the evolution of CIN in pregnant women. Design. Prospective study. Setting. Department of Obstetrics and Gynaecology, University of Insubria, Italy. Population. Women with histological CIN during pregnancy. Methods and main outcome measures. Between 2003 and 2007, women with an abnormal Pap-smear during pregnancy underwent colposcopy. Patients with histological CIN were followed during pregnancy with colposcopy every 8 weeks and post-partum evaluation was scheduled 3-6 months after delivery. Women with post-partum histological diagnosis of CIN 2-3 underwent conization. To understand the impact of pregnancy on the evolution of CIN, women with CIN 1 discovered during pregnancy were compared to a group of non-pregnant fertile patients with first diagnosis of CIN 1. Results. A total of 78 women were included: 36 (46.2%) with CIN 2-3 and 42 (53.8%) with CIN 1. In women with CIN 2-3, no invasion was suspected during pregnancy and at post-partum evaluation, no invasive or microinvasive cancer, and 19 (52.7%) persistent CIN 2-3, and 17 (47.3%) regressions were diagnosed. In the group of CIN 1, we recorded six (14.3%) progressions to CIN 2-3, seven (16.6%) persistent CIN 1 and 29 (69%) regressions. The control group of non-pregnant women had a lower regression rate (37/76: 48.7%) in comparison to pregnant women (p=0.03). Conclusions. Expectant management for CIN 2-3 diagnosed during gestation is safe. When discovered during pregnancy, CIN 1 has a significantly higher tendency to spontaneous regression in comparison to non-pregnant condition.