The decision to pursue pregnancy after breast cancer treatment raises concerns, particularly in women with hormone receptor-positive tumors, due to fears of recurrence or compromised survival. Despite growing evidence suggesting safety, uncertainty persists among both patients and clinicians. A comprehensive search of Medline, Embase, and Cochrane Library was performed through 31 March 2023 without restrictions on date or language. Studies eligible for inclusion were retrospective or prospective cohort and case-control studies, as well as clinical trials, comparing survival outcomes in premenopausal women who did or did not experience pregnancy following a diagnosis of hormone receptor-positive breast cancer. Key outcomes analyzed were disease-free survival (DFS) and overall survival (OS). Data were pooled using hazard ratios (HRs) with 95% confidence intervals (CIs). The study protocol was registered in PROSPERO (CRD42023394232).Of 7796 records screened, eight studies met inclusion criteria, totaling 3805 women, including 1285 who became pregnant after breast cancer. Median follow-up ranged from 3.8 to 15.8 years and was similar across pregnancy and non-pregnancy groups. Analysis of three studies (n = 987) reporting DFS revealed no significant difference between the two groups (HR 0.96, 95% CI 0.75–1.24, P = 0.781). In six studies (n = 3504) reporting OS, pregnancy was associated with a significantly lower risk of death compared to women who did not conceive (HR 0.46, 95% CI 0.27–0.77, P < 0.05).These findings indicate that pregnancy after hormone receptor-positive early breast cancer does not compromise survival and may even improve overall outcomes. Women with a history of this breast cancer subtype can be reassured about the safety of post-treatment pregnancy.
