No, when it comes to breastfeeding, breast size is irrelevant. The size of a woman’s breast is mostly determined by how much fatty tissue they contain.  This tissue doesnt have anything to do with milk production .

Hormones triggered by childbirth as well as nursing stimulates the mammy glands in the breast to secrete milk and push it into the milk duct under the nipple and areola. The areola is the dark area around the nipple. When  the baby sucks, the milk flows into the mouth.

Breasts gets larger once they fill with milk and even during pregnancy  as the mammy glands prepare for breastfeeding.  However the amount of milk produced is really determined by how much the baby nurses. The more your breastfeed  the baby, the more you nurse.

If your breasts doesn’t grow and change during pregnancy and stays soft in the days after delivery, you may have a condition known as Insufficient Glandular Tissue IGT.  Moms with this condition do not have enough glands in their breasts to produce enough  milk. Your doctor or lactation  consultant will assess your situation and find ways to boost your milk production or recommend you supplement with formula or donated milk.

Smoking , previous breast surgery, certain medications such as birth control pills and some medical conditions can also contribute to low milk supply.

If you are concerned about your milk supply, contact your doctor or lactation consultant.