THE EFFECT OF ROUTE OF DELIVERY ON REGRESSION OF ABNORMAL CERVICAL CYTOLOGIC FINDINGS IN THE POSTPARTUM PERIOD

OBJECTIVES: We sought to determine whether pregnant women with abnorma l antepartum cervical cytologic findings differ in their postpartum ra tes of regression with respect to mode of delivery. STUDY DESIGN: Betw een 1990 and 1997, 446 pregnant women with antepartum abnormal cervica l cytologic findings were identified. Complete demographic, clinical, and cytologic reports were available for 138 women. Papanicolaou smear data were collected and separated into three groups by use of the Bet hesda classification system (atypical squamous cells of undetermined s ignificance, low-grade squamous intraepithelial cells, and high-grade intraepithelial cells). Postpartum regression rates of antepartum Papa nicolaou smears, with respect to degree of squamous epithelial cell ab normality and mode of delivery, were analyzed by Fisher's exact and Wi lcoxon rank sum tests. RESULTS: Of the 138 women, 109 (79%) were deliv ered vaginally and 29 (21%) by cesarean section. No statistically sign ificant difference was found between women delivered vaginally and tho se delivered by cesarean section with respect to age, parity, and smok ing history within the three groups (atypical squamous cells of undete rmined significance, low-grade squamous intraepithelial cells, and hig h-grade squamous intraepithelial cells). The overall postpartum regres sion rate for the 59 women with antepartum high-grade squamous intraep ithelial cells was 48%. Of the 47 women with high-grade squamous intra epithelial cells who were delivered vaginally, 28 showed regression in the postpartum period versus none of the 12 women delivered by cesare an section (60% vs 0%, p < 0.0002). CONCLUSION: Postpartum spontaneous regression of Papanicolaou smears consistent with high-grade squamous intraepithelial cells occurs with increased frequency among women who are delivered vaginally versus by cesarean section.