To describe cancer treatment during pregnancy and maternal and infant outcomes using linked Japanese claims data, with pregnancies without a malignant neoplasm diagnosis serving as a background benchmark.
Approach:
Design and data: Descriptive cohort study using mother–infant-linked JMDC claims from January 2005 through December 2024.
Cohorts: Among 241,891 eligible pregnancies, 500 had cancer diagnosed before delivery and formed the analytical cohort; 236,002 pregnancies without a malignant neoplasm diagnosis formed the internal reference group.
Exposure and outcomes: Anticancer-agent exposure was defined as a prescription from cancer diagnosis through delivery. Treatment modalities and maternal and infant outcomes were described; outcomes were stratified by anticancer-agent exposure.
Key Findings:
Sixteen of the 500 pregnancies in the analytical cohort had a documented anticancer-agent prescription between cancer diagnosis and delivery; 484 were classified as unexposed.
The supplied article context describes the study rationale and methods but does not provide results for treatment modalities or maternal and infant outcomes.
Interpretation:
The study was designed to characterize treatment and outcomes in routine Japanese claims data. The reference group was intended as a background benchmark, not for causal inference.
Limitations:
The study included live births only.
Anticancer-agent exposure was identified from prescriptions in claims, and observed drug combinations were not confirmed treatment regimens.
The provided context does not include outcome results, preventing a summary of maternal or infant outcome comparisons.
