Women who have tissue development only in one breast produce more milk on one side and the baby prefers that side than the other.
Mothers would have noticed that their baby prefers to be fed from one breast over the other. Many have wondered what may be the reason for this, and while many worry that there may be something wrong with their breasts, research suggests there's no need to worry.
Midwife Cath Curtin, from Melbourne, Australia, explained this phenomenon on Mama Mia's Year One podcast. "A lot of women lactate better on one side," she said. "For some women, one [breast] is really big and one is really small."
Behavioural psychologist Karen Pryor and Nursing Your Baby author Gale Pryor confirmed on Baby Center that it's perfectly normal for babies to prefer one boob over the other.
"This tendency is harmless," they wrote on the site. "Your breasts will adjust to produce different levels of milk according to the frequency with which each is nursed."
They also noted that there's a benefit to letting your little one finish one breast before switching: "He'll get the rich, high-calorie hindmilk that comes at the end of each feeding."
Breastfeeding mamas are advised to switch breasts with every new feeding, but midwife Curtin reminds us that it's more important to just listen to your baby. After all, fed is best.