Natural evolution of cervical intraepithelial lesions and high-risk human papillomavirus infection during pregnancy

INTRODUCTION: The aim of this study was to investigate the pregnancy course, outcomes, and the progression, persistence, or regression status of postpartum cervical intraepithelial lesions (SIL) and high-risk Human Papillomavirus (HR-HPV) positivity in pregnant women who were diagnosed with cervical intraepithelial lesions and/or HR-HPV positivity detected through cervical Pap smear testing shortly before or at the onset of pregnancy.
METHODS: The study was conducted between 2018 and 2021 at Zeynep Kamil Women’s and Children’s Diseases Training and Research Hospital, including seventy pregnant women who were identified either with preinvasive cervical lesions in cervical cytology tests or with high-risk Human Papillomavirus (HR-HPV) positivity through Real-Time PCR testing. Pregnancy outcomes were evaluated. A control group of 146 non-pregnant patients comparable in terms of age, parity, cytology, and HPV typing results was selected. The natural evolution of cervical intraepithelial lesions and HR-HPV infection in both groups was compared using samples obtained 12–18 months after the first evaluation.
RESULTS: In the pregnant group, the regression rate of squamous intraepithelial lesions was 87.1%, whereas the rate of HPV infection regression was 68.8%. Comparatively, these rates in the control group were 64.6% and 43.0%, respectively. The regression rate of abnormal cervical cytology was significantly higher in the pregnant group (3.2%) than in the control group (23.8%), with a minimal progression rate (p=0.001). The regression rate of HR-HPV infection was significantly higher in the pregnant group than in the control group (p=0.009). When both groups were analyzed, the regression rate of squamous intraepithelial lesions in the presence of other HR-HPV types (72.6% (n=61)) was significantly higher than that in HPV 16–18-positive cases (54.1% (n=33)) (p=0.021). Of the total pregnancies, 14.7% resulted in abortion, 11.4% resulted in preterm birth, 8.7% resulted in post-term birth, and 65.2% resulted in term birth. Regarding the increase in the rate of preterm birth, there was no significant difference in preterm birth rates among HR-HPV types. There was no significant difference in the frequency of pregnancy-related complications based on HR-HPV types and the regression status of HR-HPV infection.
DISCUSSION AND CONCLUSION: Preinvasive lesions of the cervix and HR-HPV infection exhibit a high rate of spontaneous regression after pregnancy. In cases of low-grade lesions and situations without suspicion of invasive cancer, histopathological examination and definitive treatment may be considered for postponement until after pregnancy. This observed regression appears to be associated with progesterone dominance during pregnancy. Further advanced molecular and histopathological studies are required to elucidate the impact of progesterone on squamous intraepithelial lesions and cervical HR-HPV infection.

Keywords: Cervical cytology, cervical intraepithelial neoplasia, human papillomavirus, pregnancy, squamous intraepithelial lesion.