Cervical intraepithelial neoplasia and cervical cytology in pregnancy

Cervical cancer screening during pregnancy presents unique challenges for cytologic interpretation. This review focuses on pregnancy-associated cytomorphological changes and their impact on diagnosis of cervical intraepithelial neoplasia (CIN) and cervical cancer. Pregnancy-induced alterations include navicular cells, hyperplastic endocervical cells, immature metaplastic cells, and occasional decidual cells or trophoblasts. These changes can mimic abnormalities such as koilocytosis, adenocarcinoma in situ, and high-grade squamous intraepithelial lesions, potentially leading to misdiagnosis. Careful attention to nuclear features and awareness of pregnancy-related changes are crucial for correct interpretation. The natural history of CIN during pregnancy shows higher regression rates, particularly for CIN 2, with minimal risk of progression. Management of abnormal cytology follows modified risk-based guidelines to avoid invasive procedures, with treatment typically deferred until postpartum. The findings reported in this review emphasize the importance of considering pregnancy status in cytological interpretation, highlight potential problems, and provide guidance on differentiating benign pregnancy-related changes from true abnormalities. Understanding these nuances is essential for accurate diagnosis and proper management of cervical abnormalities in pregnant women.