The concern that using a breast pump causes breasts to lose their firmness, a condition known medically as ptosis, is a common worry among new parents. Changes in breast shape and position that occur after pregnancy are frequently but incorrectly attributed to the method of milk removal, whether direct nursing or pumping. The physiological changes that lead to softening and a lower position of the breast begin with the hormonal shifts of pregnancy itself, long before any milk is expressed.
Pumping: Mechanical Action Versus Structural Change
The mechanical action of a breast pump is not a primary driver of permanent breast ptosis. Medical experts agree that the gentle suction used during proper pumping is insufficient to stretch or damage the internal support structures of the breast, such as the Cooper’s ligaments. The temporary expansion and retraction of the breast tissue during a pumping session is comparable to the changes experienced during direct nursing. Structural changes are caused by the mass fluctuation of glandular tissue, a process that happens regardless of how the milk is removed.
The Primary Drivers of Breast Ptosis
The factors scientifically proven to influence breast ptosis are almost entirely related to the pregnancy experience and general lifestyle, not the lactation method. The number of pregnancies a person has is strongly correlated with the degree of ptosis, with effects increasing after each pregnancy. During pregnancy, hormones trigger the mammary glands to increase in size and number, preparing for milk production. This rapid enlargement stretches the skin and supporting ligaments, which contributes to the loss of firmness regardless of whether the mother chooses to breastfeed or pump.
Other non-pregnancy factors that significantly predict breast ptosis include a higher pre-pregnancy body mass index (BMI) and a larger pre-pregnancy bra cup size. Age is a factor, as the skin naturally loses its elasticity over time. A history of cigarette smoking is also implicated, as smoking breaks down elastin, a protein that helps support the breast.
How Glandular Tissue Changes Shape
Expansion
The internal biological process that directly leads to breast shape changes is the cycle of expansion and regression of glandular tissue. The breast is primarily composed of glandular tissue, which makes milk, and adipose (fat) tissue, which provides volume. During pregnancy and lactation, the glandular tissue proliferates, increasing in volume and displacing the surrounding fat cells. This increase in glandular mass causes the breast to become heavier and larger, further stretching the surrounding skin and connective tissue.
Involution and Ptosis
When the individual stops lactating, a process called postlactational involution begins. During involution, the secretory tissue undergoes widespread cell death, causing it to shrink back toward a pre-pregnancy state. However, the skin and ligaments that were stretched to accommodate the maximum size during lactation do not always fully retract. This discrepancy between the post-involution size of the internal tissue and the stretched elasticity of the outer skin is the physical mechanism that results in the appearance of ptosis.