THE LET-DOWN OR MILK-EJECTION, REFLEX
Signs of a Healthy Let-Down
Some milk accumulates in the milk reservoirs behind the nipple and in the ducts, but most of the milk is made and stored in other parts of the breast. The let-down reflex releases this milk into the milk ducts, making it available to the baby.
During breastfeeding, the baby’s suck stimulates the let-down. When a baby begins to nurse, the rhythmic motion of his jaws, lips, and tongue send nerve impulses to the mother’s pituitary, the master gland in the brain, by way of the hypothalamus. Two hormones, prolactin and oxytocin, are then released. It is the oxytocin that stimulates the let-down reflex, causing the band-like cells surrounding the milk-producing cells (alveoli) to constrict and squeeze out the milk from all parts of the breast. This muscle action makes the milk available to the baby by sending it through the ducts to the milk reservoirs (lactiferous sinuses) which are located within the breast beneath the areola behind the nipple.
Any of the following may be signs that the mother’s milk is letting down:
- uterine cramps and increased blood flow (during the first few days after
- a “pins-and-needles” or achy feeling in her breast (some women don’t feel this at all and some feel it only after the early weeks),
- milk leaking from the other breast,
- a change in the baby’s suck-swallow rhythm, from quick sucks to long, slow sucks with regular swallowing and a breath after every one or two sucks,
- milk appearing in the comer of the baby’s mouth,
- a feeling of relaxation in the mother.
Some mothers feel a tingling, pins-and-needles sensation with the let-down or a sharp, stabbing pain or cramp. Other mothers do not notice any sensation or feel it only occasionally. While the mother is breastfeeding, the most reliable sign of the let-down is a change in the baby’s sucking and swallowing pattern from quick sucks with occasional swallowing to long, slow sucks with regular swallowing or gulping. If the baby is gaining well, the mother can be certain that her let-down is functioning well.
A baby who is sucking well will stimulate several let-downs during the feeding, assuring that he receives the fatty hindmilk, as well as the watery foremilk that comes at the beginning of a feeding.
Delayed or Inhibited Let-Down
If the let-down is delayed or inhibited, the baby may nurse well for a minute or two and then pull away in frustration and unhappiness. The mother may notice that her baby is sucking rapidly but not swallowing deeply or often.
Some milk accumulates in the milk reservoirs near the nipple, but without the let-down reflex, most of the mother’s milk will remain in the breast despite the baby’s efforts.
During times of emotional crisis or unusual stress, some mothers find that their let-down is temporarily affected. If the mother has sore nipples, anticipating the pain may make her tense when she puts her baby to breast, delaying or inhibiting her let-down. If her nipples are sore, talk to her about possible causes and what she can do to eliminate or minimize her discomfort. (See the chapter “Positioning, Latch-On, and the Baby’s Suck.”) If the mother is engorged, her let-down also may be temporarily affected. Warm compresses, gentle breast massage, and expression of a little milk may help encourage the let-down (Lawrence, p. 252).
Use of ice has been found to inhibit the let-down, so encourage the mother to avoid applying ice to her nipples or breasts before nursing or while her let-down is delayed or inhibited (Newton and Newton 1948).
Stress, smoking (Dahlstrom 1990; Steldinger and Luck 1988), excessive alcohol (Lawrence, p. 375) or caffeine (Berlin 1984), and some drugs taken by the mother (Batagol 1989; Berlin 1989; Atkinson and Biggs 1988) can also delay or inhibit the let-down. If smoking or excessive alcohol or caffeine may be contributing factors, cutting down may improve the mother’s let-down. If the mother is taking a drug that may be interfering with her let-down, suggest she talk to her doctor about finding an alternative medication. For more information on smoking, caffeine, and drugs, see the chapter “Drugs, Vitamins, Vaccines, and Diagnostic Tests.”
A mother who is going through a serious emotional or physical crisis—such as a sudden death in the family or a car crash—may find that her let-down and milk supply are temporarily affected. In extreme situations, extra adrenalin in the mother’s system can reduce or block the release of the hormones affecting let-down and milk production (Lincoln and Paisley 1982).
If this happens, encourage the mother to try to relax and to continue breastfeeding and/or expressing so that her let-down and milk supply will quickly return to normal.
When a baby is premature or very ill, it is normal for the mother’s milk supply to fluctuate with her baby’s condition. When the mother is very worried about the baby’s health or survival, it may not be easy to express much milk. Times of crisis commonly result in a temporary decrease in milk supply. This is normal, a natural part of the complex emotions involved in having a baby in the intensive-care nursery.
If the mother’s milk supply decreases during a crisis, unsupportive comments from those around may convince the mother to give up breastfeeding entirely unless she has another source of support. Assure her that her decrease in supply is only temporary and that it will increase again as she is able to relax. Also tell her that however much milk her baby gets by breastfeeding or she is able to express will be enough to stimulate her breasts to continue making milk. It may also be comforting for her to talk to another mother who has had the same experience.
During the early weeks of breastfeeding, it is not unusual for a new mother’s let-down to take a few minutes to occur when she puts her baby to breast. But as she becomes more experienced at breastfeeding, her let-down reflex will respond more quickly and automatically when her baby sucks. Eventually, it may be triggered by other stimuli—the sight of her baby, the feel of his skin, his smell, his cry (even another baby’s cry), as well as his sucking at the breast.
If the mother has recently given birth, assure her that her let-down will function more automatically with time and practice. Allowing unrestricted nursing in a quiet, undistracted setting will help condition the mother’s body to let down her milk more automatically.
For any mother whose let-down is inhibited or delayed, relaxation exercises, warm compresses before nursing, breast massage, and a calm, undistracted setting may help encourage her let-down to occur. Focusing on the baby, stroking his hair, enjoying the feel of his skin may help a mother relax and respond to her baby. Sometimes breastfeeding lying down relaxes the mother enough to help her let-down occur more quickly.
- The let-down, or milk-ejection, reflex is triggered by hormones. It releases the milk from all parts of the breast so that it is available to the baby.
- The most reliable signs of a well-functioning let-down are a slowing of the baby’s suck-swallow pattern, deep and regular swallowing, and a healthy weight gain.
- The let-down reflex may occur many times during a feeding.
- If the let-down is delayed or inhibited, the baby may become frustrated and upset, because most of the milk in the breast is not being released.
- Ask the mother if she is under unusual stress or if she feels tense when she puts her baby to breast. Ask her if she has sore nipples or is engorged.
- Ask the mother if she smokes, drinks alcohol, drinks caffeinated beverages, has hormonal problems, or is taking any medications.
- It is normal for a mother’s let-down reflex and milk supply to be temporarily affected while she is going through a crisis.
- During the early weeks of breastfeeding, a mother’s let-down may take a few extra minutes to occur.
- Breast massage, warm compresses, relaxation exercises, a calm setting, or lying down can help the mother stimulate her let-down.