Long-Term Offspring Outcomes Following Parental Exposure to BCR::ABL1 Tyrosine Kinase Inhibitors in Chronic Myeloid Leukemia: A Retrospective Cohort Study with Follow-Up to 24.6 Years

Background: Evidence regarding long-term outcomes among offspring following maternal or paternal exposure to BCR::ABL1 tyrosine kinase inhibitors (TKIs) is limited. We described pregnancy outcomes and offspring health through adolescence and early adulthood in a single-centre cohort of patients with chronic myeloid leukemia (CML). Methods: This retrospective, descriptive cohort study included patients with chronic-phase CML who experienced a pregnancy, or whose partner experienced a pregnancy, in association with TKI exposure and for whom longitudinal offspring follow-up was available. Long-term offspring outcomes were ascertained from detailed obstetric and pediatric medical records supplemented by parental reports. Fourteen patients (nine women and five men) contributed 21 pregnancy events and 23 live-born offspring, including two twin pregnancies in the paternal-exposure group. Results: In the maternal-exposure group, median gestational age at delivery was 38.0 weeks (range, 35–40), and four of 15 deliveries were preterm. In the paternal-exposure group, median gestational age was 39.0 weeks (range, 38–41), with no preterm deliveries. Median offspring follow-up was 252 months (range, 212–295), extending through adolescence and into early adulthood. One offspring had a primum atrial septal defect that was surgically corrected. No additional clinically documented major abnormalities in growth or developmental progress were identified during available follow-up. Given the small cohort, these observations were interpreted descriptively and were not considered evidence of equivalence with population-level rates. Conclusions: This small retrospective cohort provides unusually long observational follow-up of offspring after selected maternal or paternal TKI exposures. The findings are clinically informative but cannot establish reproductive safety or exclude rare adverse outcomes. Larger multicentre registries using standardized long-term developmental, neurocognitive, and endocrine assessments are needed.