Does Uneven Breast Size Affect Nursing?
QUESTION
Dear Lactation Consultant,
I'm expecting a baby in September. I have un-even breasts. One is an "A" cup; the other a "C" cup. When my breasts become full of milk will the smaller one get bigger and by how much?
ANSWER
This is a very common concern. I can't predict exactly how large your breasts will be once your baby arrives, but I can tell you that they will get larger once your milk comes in. Some women notice an increase of several cup sizes, while others find that most of the increase in size occurred during pregnancy, and their breasts only get one size larger once their baby is born.
I can assure you that it's normal for one breast to be larger than the other, and for one to produce more as well. The two breasts are independent, and aren't like mirror images of each other. That's why most moms who double pump will get different amounts from each breast, and also why so many babies develop a preference for one side over another.
In some women, it's a subtle difference, in others it can be dramatic -- five or six ounces from one breast and one from the other. It is somewhat unusual for the difference in size to be so pronounced during pregnancy, but it isn't unheard of. Breast changes during pregnancy cause the development and increase in size of milk producing tissue, so the fact that one side has developed so much more than the other may mean that for whatever reason, the milk producing tissue is developing a lot more on one breast than the other. In situations like this, it is reasonable to expect that the larger breast will produce more milk than the other, although that isn't always the case.
Because anatomical differences account for the discrepancy in size and production, then extra stimulation (via nursing or pumping) on the smaller side usually doesn't make much difference.
Other than looking lop-sided (ever stuff your bra when you were a teenager? -- it still works...) it shouldn't cause a problem. Women with only one functioning breast can still produce plenty of milk for their babies. Babies will take what they need, and the larger breast will respond to supply and demand. If your baby is not gaining weight well, then you will need to address that issue separately (see article on Increasing Milk Supply)I wouldn't worry about this in advance. The only reason for having two breasts instead of one is that your body is designed to nurse twins if necessary, so there should be no reason that you can't produce enough milk for one baby even if one side produces much more than the other.
Hope this info is helpful, and I wish you all the best.
-- Anne, IBCLC
Kathleen Tackett
Dr. Kendall-Tackett is a health psychologist, International Board Certified Lactation Consultant, and Research Associate Professor of Psychology specializing in women's health at the Family Research Lab, University of New Hampshire. She is a Fellow of the American Psychological Association in both the Divisions of Health Psychology and Trauma Psychology. Dr. Kendall-Tackett is a La Leche League leader, chair of the New Hampshire Breastfeeding Taskforce, and the Area Coordinator of Leaders for La Leche League of Maine and New Hampshire.
Dr. Kendall-Tackett is author of more than 140 journal articles, book chapters and other publications, and author or editor of 15 books including The Hidden Feelings of Motherhood (2005, Hale Publications), Depression in New Mothers (2005, Haworth), and Breastfeeding Made Simple, co-authored with Nancy Mohrbacher (2005, New Harbinger). She is on the editorial boards of the journals Child Abuse and Neglect, Journal of Child Sexual Abuse and the Journal of Human Lactation, and regularly reviews for 27 other journals in the fields of trauma, women's health, interpersonal violence, depression, and child development. Dr. Kendall-Tackett is the "Ask a Lactation Consultant" columnist on Pregnancy.org and serves on the Board of Directors of Attachment Parenting International.
Dr. Kendall-Tackett received a Bachelor's and Master's degree in psychology from California State University, Chico, and a Ph.D. from Brandeis University in social and developmental psychology. She has won several awards including the Outstanding Research Study Award from the American Professional Society on the Abuse of Children, and was named 2003 Distinguished Alumna, College of Behavioral and Social Sciences, California State University, Chico.
