Association of gravidity, parity, and abortion history with nodal metastasis in women with papillary thyroid carcinoma: a retrospective cohort study.

Background: Papillary thyroid carcinoma (PTC) predominantly affects women, particularly during the reproductive years, suggesting that reproductive factors may influence not only tumor occurrence but also metastatic behavior. However, evidence regarding the association between reproductive history and lymph node metastasis (LNM) in women with established PTC remains limited. Methods: We conducted a retrospective cohort study of 1,828 women with pathologically confirmed PTC who underwent initial surgery. The primary outcome was any cervical lymph node metastasis (LNM). Secondary outcomes included isolated central lymph node metastasis (CLNM) and combined central and lateral lymph node metastasis (CLNM+LLNM). Multivariable logistic regression models were used to evaluate the associations between reproductive history, gravidity, parity, and abortion history and nodal outcomes. Reproductive variables were analyzed in separate models to reduce collinearity. Sensitivity and subgroup analyses were performed to examine the stability of the observed associations. Results: Cervical LNM was identified in 903 patients (49.4%). In the primary adjusted model, ever pregnancy was associated with lower odds of any LNM (adjusted OR 0.420, 95% CI 0.276-0.640; Conclusions: In women with PTC, ever pregnancy was associated with lower odds of cervical LNM, particularly for central compartment disease. This association appeared to be more closely related to ever having been pregnant than to a linear increase in gravidity or parity. Reproductive history may provide supplementary context for nodal risk assessment, but it should not replace established clinicopathological factors or independently alter surgical decision-making.