An increase in the incidence of breast cancer in women aged < 40 years in conjunction with a pronounced shift towards later childbearing has been reported in recent years. Because survival from breast cancer in women of childbearing age has significantly improved, they are often concerned whether subsequent pregnancy will alter their risk of disease recurrence. In the modern era, the prognosis of pregnancy-associated breast cancer is comparable to non-pregnancy-associated breast cancer and women can bear children after breast cancer treatment without compromising their survival. Therefore, they should not be discouraged from becoming pregnant, and currently the usual waiting time of at least 2 years after the diagnosis of breast cancer is recommended. However, a small, nonsignificant adverse effect of pregnancy on breast carcinoma prognosis among women who conceive within 12 months of breast cancer diagnosis and a higher risk of relapse in women younger than 35 up to 5 years of the diagnosis may be found. Fortunately, for women with localized disease, earlier conception up to six months after completing their treatment seems unlikely to reduce their survival. Ongoing and future prospective studies evaluating the risks associated with pregnancy in young breast cancer survivors are required.