Why does having your first baby after age 30 increase your breast cancer risk? More so than being childless?

-The hormonal changes that occur during pregnancy may influence a woman’s chance of developing breast cancer later in life. -Some factors associated with pregnancy may reduce a woman’s chance of developing breast cancer later in life. -Some factors associated with pregnancy may increase a woman’s chance of developing breast cancer. -Induced abortion and miscarriage have not been shown to increase a woman’s chance of developing breast cancer. -Pregnancy may reduce a woman’s chance of developing some other cancers, including ovarian and endometrial cancers, later in life. -Breastfeeding for an extended period (at least a year) is associated with a decreased risk of both hormone receptor-positive and hormone receptor-negative breast cancer

I read that it might be because a woman how starts young, or has a lot, has fewer periods over her life. I think that it might also be that when we use our bodies the way they were intended it is healthier for us. Oh, I don't suggest we have babies as teens, or have a bunch, but the breastfeeding example made me think of it. If we use our breasts for their designed purpose they are healthier. That is my opinion! The risk isn't much, so if you wait until after 30 that is fine. Other things will be better for you. Probably less stress over money, since you are apt to be more secure.

I heard that the risk is a tad bit higher if you wait til your over 30 to have your first child. Never heard of having a first child over 30 being higher than that of a woman who never had children at all though.

I think you found some misinformation. I had my son after 30 and my docs told me no such thing. My pregnancy was high risk too, not to mention a family history of breast cancer.