Incidentally detected papillary thyroid carcinoma does not impair pregnancy outcomes during fertility treatment

Papillary thyroid carcinoma (PTC) is more common among women, including those of reproductive age. While a cancer diagnosis may influence pregnancy planning and treatment decisions in women receiving fertility treatment, the impact of PTC management on pregnancy outcomes remains unclear. We aimed to evaluate the clinical course of PTC diagnosed during fertility treatment and to clarify whether pregnancy outcomes differ according to the initial management strategy, surveillance or surgery.

We retrospectively analyzed reproductive-age women diagnosed cytologically with PTC prior to pregnancy, who were referred to Ito Hospital for thyroid evaluation between January 2013 and December 2019, during fertility treatment. PTC cases were classified according to the Japanese Thyroid Tumor Treatment Guidelines 2018. Patients were followed for clinical course and pregnancy outcomes through December 2024.

Among 17 713 women undergoing fertility evaluation, 240 were diagnosed with PTC. Median age was 38 years, and most cases were classified as very low-risk (59.6%), followed by low-risk (27.1%) and intermediate risk (13.3%), with no high-risk cases. Among 96 surveillance patients followed for ≥12 months, disease progression occurred in 8 patients (8.3%), including 1 case during pregnancy. Patients who achieved live birth were significantly younger than those who did not (P < .001). Management strategy (surgery or surveillance) was not associated with the likelihood of live birth (P = .1868).

Both surveillance and surgery can be safely integrated into fertility care for women with reproductive-age PTC. Tumor progression was rare and pregnancy outcomes were primarily influenced by maternal age rather than treatment strategy.