Related Experiment Video
Updated: Jun 26, 2026

Z-Scores for Assessing Ovarian Reserve in Young Patients Undergoing Fertility Preservation
Published on: October 25, 2024
Breast cancer incidence after hormonal infertility treatment in Sweden: a cohort study
Chantal C Orgéas1, Karin Sanner, Per Hall
1Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden. Chantal.Orgeas@ki.se
Objective:
To assess the impact of infertility treatment with causes of infertility on incidence of breast cancer.
Study Design:
Historical prospective cohort study of 1135 women attending major university clinics for treatment of infertility in Sweden, 1961-1976. Women were classified as users of clomiphene citrate or gonadotropins, or a combination of both therapies. Standardized incidence ratios were calculated to estimate relative risk of breast cancer.
Results:
We observed 54 cases of breast cancer during 1961-2004, which did not significantly exceed those expected. Users of high-dose clomiphene citrate had an almost 2-fold increased risk (standardized incidence ratio, 1.90; 95% confidence interval, 1.08-3.35). This association was more pronounced among women referred for nonovulatory factors, with 3-fold increased risk (standardized incidence ratio, 3.00; 95% confidence interval, 1.35-6.67).
Conclusion:
No overall increased risk for breast cancer was shown with infertility treatment. Women with nonovulatory causes treated with high-dose clomiphene citrate therapy may have an elevated risk for breast cancer.
Related Concept Videos
Infertility in Females
Endometriosis, a condition characterized by abnormal growth of endometrial...
Infertility in Males
Cancer Survival Analysis
Disorders of the Female Reproductive System