Thursday's Tip: Does breast size matter when you are breastfeeding?

By LLLC Blog, 28 January, 2016

Many pregnant women worry about whether their breasts are too small to produce enough breastmilk. Women with larger breasts tend not to worry about their breast size in relation to future milk production. Other people also don’t tend to suggest to them that they ought to worry as can happen to their smaller cup sized sisters. So, does size matter when it comes to breastfeeding?

First we need to look at what a breast is made up of.

A breast consists of:

Glandular tissue: which makes milk and transports it to the nipple

Connective tissue: muscles and ligaments which support the structure of the breast

Fatty tissue: this provides protection to the other tissues and structures within the breast

Nerves: provide the sensitive to touch that is part of the milk ejection process

Blood: brings the nutrient ingredients to the breast to create breast milk '

Lymph: removes the cellular level waste products from the breasts.

The size of any woman’s breasts is determined mostly by the amount of fatty tissue in the breast. Fatty tissue is not involved in the production of breastmilk.

During pregnancy the amount and density of glandular tissue increases and during the lactation period, on average, there is about twice as much glandular tissue as fatty tissue present in the breast. Approximately 70% of the glandular tissue is found within a 30 mm (one inch) radius of the nipple. Thus a baby with a good deep latch is reaching the majority of the glandular tissue when he compresses his jaws during a feeding.

A more important indicator of future milk production than breast size before pregnancy is an increase in breast size during pregnancy. Needing bigger bras as the pregnancy moves along is a clear indicator that the glandular tissue is developing. Mothers who notice minimal or no change in breast size during their pregnancy should be in contact with a lactation specialist before baby arrives so that they can, together, keep a careful eye on baby’s weight gain in the early weeks.

Most women’s breasts are not identical in size or shape at any time during their life span. For the majority these slight differences aren’t noticeable prior to pregnancy. Some mothers find that their breasts become more obviously different in size and shape when they are pregnant and lactating. There may be more glandular development on one side than the other due to a past injury to the breast or for unknown reasons. The difference in size and/or shape may or may not have an influence on milk production, milk storage capacity or baby’s preference for one side over the other.

The breast’s storage capacity varies from individual to individual and may be one factor that explains the differences in breastfeeding frequency between one breastfeeding pair and another. Breast storage capacity is the maximum volume of milk available to the baby when the breast is at its fullest. In studies the measured storage capacity ranged from 2.6 oz (74 g) to 20.5 oz (606 g). Babies of the mothers with a smaller storage capacity will naturally be feeding more frequently to take in the same overall volume of milk during the course of a day. Breast storage capacity is not related to breast size because the storage capacity is created by glandular tissue not fatty tissue.

Breast size may influence breastfeeding in the early days as mum and baby are getting positioning figured out. Mothers with very large breasts may find it more challenging at first to get baby properly positioned for an effective latch. The size and shape of mum’s breasts (larger or smaller) may also influence the position she finds most comfortable for holding baby at the breast.

Regardless of your breast size if you have questions or concerns about milk production, frequency of feedings or positioning and latch please contact a La Leche League Canada Leader to get more information and support. Because breastfeeding isn’t always easy, we’re here to help.

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