Cancer treatment is associated with a measurable decrease in live births in a large, population-based study.

Objective: To define the live birth rates in a large, population-based study of the most common reproductive-age cancers in women.

Design: Retrospective cohort study.

Setting: Population-based study.

Patients: Female cancer patients diagnosed with cancer at age 18 years old or older between 1952-2014 (n = 17,952) were compared to fertility of non-cancer controls (n = 89,436).

Interventions: Live births in cancer survivors were compared with those in healthy, age-matched controls. Cases and controls were matched in the ratio of 5:1 for birth year, birthplace (Utah, yes/no), and follow-up time in Utah.

Main Outcome Measure: Rate of at least one live birth, reported as an incidence rate ratio (IRR).

Results: Of all cancer survivors, 3,127 (17.4%) had at least 1 live birth after treatment in comparison to 19,405 healthy, age-matched controls (21.7%) with the same amount of time exposure for attempting pregnancy. Breast cancer was the most common cancer type (23.1% of patients in cohort). Compared with age-matched, healthy controls, IRR of live birth was 0.69 (95% confidence interval [CI], 0.67-0.70) for all cancer types, 0.25 (95% CI, 0.20-0.33) for leukemia, 0.40 (95% CI, 0.28-0.59) for gastrointestinal cancers, 0.44 (95% CI, 0.41-0.48) for breast cancer, 0.53 (95% CI, 0.47-0.59) for central nervous system cancers, and 0.57 (95% CI, 0.44-0.73) for soft tissue cancers. With all cancer types stratified by age at diagnosis, IRR for live births in cancer survivors aged >41 years at diagnosis was 0.48 (95% CI, 0.44-0.52); IRR was 0.64 (95% CI, 0.61-0.67) in the group aged 31-40 years and 0.71 (95% CI, 0.69-0.74) in the group aged 18-30 years after their cancer treatment.

Conclusions: Cancer and its treatment were associated with lower live birth rates when comparing women with cancer vs. age-matched, healthy controls.