Popsugar Fitness Healthy Living Breast Cancer Risk Factors The 13 Biggest Risk Factors For Breast Cancer — 5 of Which You Can Change October 14, 2019 by Christina Stiehl View On One Page Photo 9 of 13 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 9 You Can Change: Pregnancy History If you had your first pregnancy after age 30, didn't breastfeed, or never had a full-term pregnancy, it can raise your breast cancer risk. Previous Next Start Slideshow Healthy LivingHealthBreast Cancer