Childbearing in women diagnosed with cancer during reproductive age

Introduction: Fertility after cancer represents a growing clinical concern. This study assessed childbearing outcomes among women diagnosed with cancer during reproductive age between 2012 and 2017 in Lombardy, the largest region in Italy. Material and Methods: Women aged 15–45 years with a primary diagnosis of cancer recorded in hospital discharge records from regional healthcare databases were selected. Each woman diagnosed with cancer was matched with up to five cancer-free women of the same age at diagnosis. The cumulative probability of childbirth up to December 31, 2022 was estimated using the Kalbfleisch–Prentice cumulative incidence function estimator. Cox regression models were used to estimate the cause-specific hazard ratios (HRs) and the 95% confidence intervals (CIs) of childbirth according to the cancer diagnosis. Furthermore, in the group of cancer survivors, exposure to antineoplastic treatment was considered and included in the model as a time-dependent covariate. Finally, a log-binomial regression model was used to assess the association between antineoplastic therapy and medically assisted reproduction. Results: A total of 13,877 women were diagnosed with cancer at reproductive age during the study period (1.16 per 1000 person-years). The cumulative probability of childbirth was lower among women diagnosed with cancer compared to cancer-free women across all age groups: 31.4% vs 32.2% (p = 0.02) among those diagnosed under 30, 13.3% vs 22.7% (p < 0.01) among those aged 30–39, and 0.8% vs 1.6% (p < 0.01) among those aged 40 and over. The corresponding HRs were 0.93 (95% CI: 0.83–1.05), 0.58 (95% CI: 0.53–0.64), and 0.52 (95% CI: 0.40–0.68). When analyses were stratified by time since diagnosis, the reduced probability among cancer survivors was confirmed to be significant only within the first 5 years after diagnosis, also for younger individuals. Antineoplastic treatment was associated with a reduced probability of subsequent birth (HR = 0.46, 95% CI: 0.39–0.52). Moreover, the therapy was positively associated with medically assisted reproduction (RR = 1.71, 95% CI: 1.14–2.56). Conclusions: The probability of childbearing was reduced within the first 5 years of diagnosis, regardless of the patient's age. A more pronounced reduction was observed in women diagnosed after the age of 30. Age and antineoplastic therapy were key factors in determining childbearing in women diagnosed with cancer.