流行病学证据表明多产可保护免患乳腺癌。近期有研究报道,与无产或单产妇女相比,生产2～10胎的妇女患乳腺癌的机率仅0.54。至于这一现象的机制意见各异。有人提出“胚胎抗原假说”,指出胚胎细胞携带与乳腺癌细胞相似的抗原,这一抗原在孕期能特异性地刺激妇了的免疫系统产生持序性保护以免乳腺癌发生。然而,几乎没有证据支持“胚胎抗 Epidemiological evidence suggests that prolificity protects against breast cancer. Recent studies have reported that women who produce 2 to 10 births have a 0.54 chance of developing breast cancer compared with women who have no birth or a single birth. As for the mechanism of this phenomenon, opinions vary. Some people put forward the “embryonic antigen hypothesis” that embryo cells carrying antigens similar to breast cancer cells, this antigen during pregnancy can specifically stimulate women’s immune system to produce orderly protection against breast cancer. However, there is little evidence to support "embryo resistance