Atypical cells in pregnancy and postpartum smears

The cytologic changes of pregnancy and the postpartum period are presented. Atypical cells were identified in 12% of smears; the majority of these atypical cells were related to degenerating decidual cells. Cells thought to represent changes due to folic acid deficiency are also described, and the features that help separate decidual cells from other cell types in the genital tract are illustrated. True neoplasia, when present, tended to persist after delivery, and these cells should not be confused with pregnancy-associated atypia.