possible causes genetics sometimes influence the size of breasts but some women may also suffer from malnutrition and a dangerously low body fat content that leads to small breasts a common occurrence among new mothers is the inability to produce any milk or a limited ability to produce only a small amount of milkonsiderations some women choose to receive breast implants to increase the perceived size of their breasts this can have both cosmetic and social benefits but it does not boost the milk producing capabilities of a woman s breasts and does not increase the likelihood of being able to provide milk to a child