Pregnancy Outcomes After a Breast Cancer Diagnosis: A Systematic Review and Meta-analysis.

Improvements in local and systemic treatment, along with earlier diagnoses through breast awareness and screening, have led to increases in survival and a decline in breast cancer (BC) recurrence. To the best of our knowledge, no meta-analysis has yet focused on pregnancy outcomes after BC treatment. Hence, our research group explored the reproductive outcomes (pregnancy, miscarriage, termination of pregnancy, live births) after BC treatment. The Embase, MEDLINE, PubMed, and Scopus databases were searched. Studies were included that reported on pregnancy and reproductive outcomes after treatment of BC. A meta-analysis of 16 studies with subgroup analyses was conducted. In the matched cohort and case-control studies (n = 1287), subgroup analysis showed that women who had received systemic therapy after surgery had an overall pooled estimate of 14% (95% confidence interval [CI], 0.12-0.16; I2  = 95.4%) of becoming pregnant. Of those who became pregnant, 12% (95% CI, 0.08-0.16; I2  = 65.9%) experienced a miscarriage. For the population-based studies (n = 711), the estimated pooled pregnancy rate was 3% (95% CI, 0.02-0.03; I2  = 85.1%) for women who became pregnant after BC treatment. The pregnancy rate after BC treatment for survivors was on average 40% lower than the general population pregnancy rate. Women with BC should be informed about the subsequent adverse effects of BC and its treatments on conception. With the increasing trend for women to defer childbirth to later in life, provision of fertility-related information, access to fertility preservation, and fertility-related psychosocial support should be offered to women of a reproductive age before they begin BC treatment.