分娩前乳腺处于部分未分化状态，故易遭受子宫内增加癌变危机的影响，Adami等曾提出人类乳腺癌起源于子宫内的假说，后者与雌激素和妊娠时所生成的激素有关。胎儿的生长与雌激素浓度呈正相关，有些作者还认为出生时体重和胎盘重量与乳腺癌的危机有关，但也有不同的意见。为此作 Before the delivery, the breast is in a partially undifferentiated state, so it is vulnerable to the crisis of cancer in the uterus. Adami et al. proposed the hypothesis that human breast cancer originated in the womb. The latter is related to estrogen and hormones produced during pregnancy. The growth of the fetus is positively correlated with the concentration of estrogen. Some authors also believe that birth weight and placental weight are related to the crisis of breast cancer, but there are also different opinions. For this purpose