Breasts change markedly during pregnancy—growing in size, changing shape, and getting heavy. As the milk ducts develop, there are often new lumps and bumps present, so it’s hard to detect breast cancer during pregnancy. That being said, when imaging is needed to help figure out if a palpable lump is worrisome, any of the tools available are safe, including mammograms.
Usually, the first line for palpable masses in pregnancy is a breast sonogram, which uses the same soundwave technology used to image your baby in your uterus. When needed, mammography is safe as well as the amount of radiation is low, and the radiologist will provide a lead apron to cover your abdomen.
It’s worth noting that screening mammograms in asymptomatic people aren’t usually done during pregnancy.