Breast milk production is a complex biological process. When the body’s milk supply decreases or ceases, it is often referred to as the milk supply ‘drying up.’ Recognizing the factors that contribute to this reduction can help in addressing or preventing it.
Insufficient Milk Removal
Breast milk production operates on a supply and demand basis. The more frequently and effectively milk is removed from the breasts, the more the body is signaled to produce. Conversely, when milk is not removed adequately or often enough, the body interprets this as a reduced need, leading to a decrease in supply.
Infrequent or missed feeding and pumping sessions directly impact this balance. Each missed opportunity to empty the breast signals the body to slow down production, as milk accumulation inhibits further synthesis. This can occur if a baby sleeps for long stretches, or if a parent is unable to pump at regular intervals due to external demands.
A baby’s ability to effectively transfer milk is also crucial. A poor latch, where the baby does not properly attach to the breast, can result in ineffective suckling. This means the baby is not removing enough milk, even if at the breast for extended periods. Anatomical issues in the infant, such as a tongue tie, can also hinder their ability to create the necessary suction and compression for efficient milk removal.
Supplementing with formula or other liquids reduces the baby’s demand for breast milk. When a baby consumes formula, they are less hungry, leading to fewer breastfeeding sessions and less milk removal. The use of pacifiers can satisfy a baby’s sucking reflex without stimulating milk production, potentially reducing feeding frequency and direct nursing time. Scheduled feedings, rather than feeding on demand, can also disrupt the supply-and-demand mechanism, as they may not align with the baby’s natural hunger cues and the mother’s milk production cycles.
Maternal Health and Hormonal Factors
Breast milk production is intricately linked to a parent’s hormonal balance and overall health. Various physiological conditions can disrupt this delicate system, impacting the body’s ability to produce or release milk effectively. Hormones like prolactin, responsible for milk production, and oxytocin, which facilitates milk ejection, must function optimally.
Pre-existing medical conditions can significantly influence milk supply. Conditions such as Polycystic Ovary Syndrome (PCOS) can affect hormonal levels, potentially leading to lower milk production. Thyroid disorders, including hypothyroidism and hyperthyroidism, can interfere with the metabolic processes necessary for milk synthesis. Uncontrolled diabetes can also pose challenges, as high blood sugar levels can impact the hormonal pathways involved in lactation.
Retention of placental fragments after birth can inhibit milk production postpartum. The placenta produces progesterone, a hormone that suppresses milk production during pregnancy. If fragments remain, they can continue to release progesterone, thereby delaying or inhibiting the full onset of lactation. This hormonal lingering prevents the necessary drop in progesterone that signals the body to begin robust milk synthesis.
Past breast surgeries, such as reductions or augmentations, may affect milk supply depending on the extent of the procedure. If milk ducts or nerves were significantly damaged or severed during the surgery, it could impair the breast’s ability to produce or release milk effectively. A new pregnancy also brings about significant hormonal shifts, particularly a rise in progesterone, which naturally signals the body to prepare for a new gestational period and can lead to a decrease or cessation of milk production from the current lactation.
Medications and Substances
Certain medications and substances can inadvertently reduce milk supply by interfering with the hormones or physiological processes involved in lactation. Awareness of these potential effects is important for breastfeeding parents.
Hormonal birth control methods, especially those containing estrogen, are known to decrease milk production. Combined oral contraceptives, for example, can suppress prolactin levels and interfere with the milk ejection reflex. Decongestants containing pseudoephedrine, commonly found in cold and allergy medications, can also reduce milk supply. Pseudoephedrine has a drying effect on mucous membranes, which can extend to the mammary glands, decreasing fluid availability for milk production.
Certain antihistamines, particularly older generations, can have a similar drying effect, potentially leading to a reduction in milk volume. Excessive consumption of alcohol can temporarily inhibit the milk ejection reflex, making it harder for milk to be released from the breast. While moderate alcohol consumption is generally considered compatible with breastfeeding, heavy drinking can suppress oxytocin release and affect milk supply.
Nicotine, whether from smoking or vaping, is another substance that can negatively impact milk production. Nicotine can reduce prolactin levels and interfere with the milk ejection reflex, leading to decreased milk volume and slower milk flow. While some herbal remedies are promoted to increase milk supply, others can have the opposite effect, so it is always advisable to consult a healthcare professional before taking any new supplement while breastfeeding.
Lifestyle and Other Contributors
Beyond direct physiological or medical causes, various lifestyle factors can contribute to a decrease in milk supply. These factors often act as secondary or contributing influences rather than primary causes.
High levels of chronic stress or anxiety can impact hormonal balance, potentially suppressing oxytocin, the hormone responsible for milk let-down, and prolactin, which facilitates milk production. When a parent is under significant emotional duress, the body’s priority shifts, sometimes affecting milk synthesis. Inadequate maternal nutrition or hydration can also play a role, as the body requires sufficient calories and fluids to produce milk effectively. While the body prioritizes milk production, severe nutritional deficiencies or dehydration can still compromise supply.
The return of menstruation, which often signals a shift in hormonal balance, can cause a temporary dip in milk supply for some individuals. This is typically due to the fluctuating levels of estrogen and progesterone throughout the menstrual cycle. Infant-related issues can also indirectly affect milk supply. For example, if an infant has a tongue tie or other oral anatomical issues that prevent them from transferring milk effectively from the breast, the lack of sufficient milk removal will signal the parent’s body to produce less milk over time, contributing to a decrease in supply.