In subgroup analyses, there was no significant increase in breast cancer risk whether in BRCA1 mutation carriers (pooled OR 1.18, 95% CI 0.81-1.72), BRCA2 mutation carriers (pooled OR 0.54, 95% CI 0.09-3.34), or in the women treated with <i>in vitro</i> fertilization (pooled OR 0.75, 95% CI 0.51-1.1), clomiphene citrate (pooled OR 1.07, 95% CI 0.78-1.45) or gonadotropins (pooled OR 1.32, 95% CI 0.8-2.18). Here, BRCA2 is linked to breast cancer.