Introduction/Background The purpose of the study was to examine the natural history of cervical HSIL during pregnancy and to determine the impact of mode of delivery on HSIL outcomes.

Methodology Data from 65 pregnant women with HSIL of the cervix from 2007 to 2022 were obtained. The median age was 30.72 years (range 22.00 – 42.98). The median gestational age at the first examination during pregnancy was 15 weeks (range 6.00 – 34.00). The diagnosis was made by a colposcopy-directed biopsy of the cervix. Pregnancy in all patients proceeded without complications.

Of the 65 women, 44 (67.69%) gave birth vaginally, 21 (32.31%) by caesarean section. In the postpartum period, 23 patients underwent conization, 20 – amputation, and 2 - hysterectomy; the remaining 20 patients: 6 – underwent ablative procedures and 14 – dynamic observation.

Results Postpartum regression of HSIL was noted in 14/65 (21.54%) cases, persistence – in 51/65 (78.46%). Postpartum regression of HSIL was observed in 12/44 (27.27%) women who gave birth vaginally and in 2/21 (9.52 %) who had a cesarean section (p = 0.013). Among women who delivered vaginally and by cesarean section, 32/44 (72.72%) and 19/21 (90.47%), respectively, had persistent HSIL lesions after delivery (p = 0.09).

Median follow-up was 57.43 months (range 8.23 – 179.85). Progression of the disease was recorded in 3/65 (4.62%) patients.

Conclusion According to our data, postpartum regression of HSIL was observed in 21.54% cases. In those who gave birth vaginally, the regression was statistically significantly higher, which indicates that the presence of HSIL in pregnant women is not an indication for cesarean section. The persistence of the disease in 78.46% of cases and progression to cancer in 4.62% clearly demonstrate the need to perform excisional procedures on the cervix in the postpartum period, which would simultaneously be both diagnostic and therapeutic in nature.

Disclosures We have nothing to disclose.