At the same time that baby’s suckling triggers the release of prolactin, it is also triggering the release of oxytocin, the hormone that causes muscle-like cells around the alveoli to contract and squeeze milk into the ducts for delivery to the baby. This process of releasing milk is called milk ejection, which is often less accurately referred to as the “let-down” response. Without this reflex, milk cannot be removed, and when not removed, the breast receives the message to cut back on milk production. For this reason, milk ejection is a critical component of the big picture of milk production.  Fortunately, the process of milk ejection works extremely well the vast majority of time. There are a few situations, such as cigarette smoking or thyroid problems, that can negatively affect milk ejection and lead to lower milk production over time.

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Mothers are often surprised to discover that milk ejections are not one-time events during a single feeding session.  The milk ejection reflex can be triggered multiple times during a breastfeeding or pumping session (up to twelve have been recorded,(13) but the average during breastfeeding is 2.5).(14)  The result is several separate spurts of milk flow beginning with an average of one ounce (30 cc) per ejection and decreasing in amount each time as the breast empties.(15) A small number of women may eject a larger quantity of milk at one time; as much as 140 gms (4.67 oz) have been recorded for one ejection. On average, however, the more milk ejections a mother has, the more milk the baby tends to consume during a feeding.(16) 

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Babies generally learn to anticipate whatever pattern their mothers’ milk ejections follow.  A hungry baby will continue to suckle off and on when the milk is not flowing strongly, hoping to trigger another ejection. In the early days, however, some babies may become upset if the milk ejection reflex does not happen right away, pulling away in anger or frustration. Over time and with positive experiences, baby learns that the milk really is there (with a normal milk supply), and he learns to trust the breast while his mother learns to trust that her milk will flow, and they both begin to relax into a mutually trusting breastfeeding relationship.  When milk production and flow are low, some babies may remain distrustful until the flow is improved, compounding the difficulty in getting the breastfeeding relationship going.

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Oxytocin release is unique in that it is not controlled exclusively by sensory (touch) stimulation, but can also be triggered by thoughts and feelings, as many breastfeeding mothers can attest who heard a baby cry in a shopping center and looked down to see wet spots on their shirts.

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If you do find that your milk ejection is taking a while to happen, the following physical techniques may help to trigger it. These may be especially helpful if baby is not breastfeeding long enough or vigorously enough and you must pump for additional stimulation.

 

Warmth     
Many mothers find that warm, moist compresses, applied to the breasts just prior to nursing or pumping, makes milk ejections happen more easily.  There are commercial products for moist heat, but you can make your own by filling a tube sock with uncooked (not instant) rice, and sewing or tying the end closed.  Lightly dampen the sock and microwave for 30 seconds or so, testing to make sure the sock is not too hot.  The shape of the sock allows it to be wrapped comfortably around the breasts.  You may also find that a warm, wet washcloth is very helpful. Hot showers are famous for initiating milk ejection, although they may not always be convenient. You can even try nursing your baby in a warm bath.

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Rubs and Massages

Breast massage before a feeding or pumping session not only helps to work milk down closer to the nipple, but it also may help to trigger milk ejection.  Experiment with light touch versus a deeper, firmer massage.  Shoulder massages and back rubs also seem to have an effect on the reflex. One particularly effective method is to have someone “spine walk” with their knuckles on either side of your spine, from the neck to your waist. This may trigger a shiver or chill sensation, which seems to trigger the milk ejection reflex as well. Another technique is to have someone massage your shoulder at a point close to the neck as you are nursing or pumping.  This stimulates an acupressure point that some mothers have found triggers milk ejection.  At the very least, you should be feeling more relaxed after some “spa” treatment!

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Nipple Stimulation

Nipple stimulation, such as gentle tickling, rolling or pulling, can be effective to encourage milk ejection when a mother is feeling stressed or anxious.  Reverse Pressure Softening (RPS) can also be helpful. The tactile stimulation of any of these techniques results in oxytocin release, which not only causes milk ejection, it induces a feeling of calm and well-being, which helps soothe stress and encourage additional milk ejections. 

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Synthetic Oxytocin Spray

Synthetic oxytocin spray has been used effectively by many nursing mothers to overcome physiological or psychological issues that inhibit milk ejection.  However, a recent study of mothers of preterm infants who used unmarked sprays containing either synthetic oxytocin or saline suggests that its effectiveness may be nothing more than a placebo effect because all mothers in the study had the same improvement in milk ejections.(1)  Another study of three women paralyzed from the neck down demonstrated effective milk ejection with the use of synthetic oxytocin spray.(2)  So the jury is still out on whether or not it works, but because many women find that it does, it may be worth trying.  There are no commercial synthetic oxytocin spray products currently available in the North America, however, a compounding pharmacist can make it by prescription by combining other ingredients.

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Conditioning the Milk Ejection Reflex

A recent study found that milk ejection is, at least in part, a conditioned response.(3)  Having a special nursing station where you take the baby to nurse creates a psychological routine that helps to train the milk ejection response.  Just as we see delicious food on TV and our salivary glands activate, “letting down” saliva into our mouths, we can condition ourselves to let down our milk when we are in specific situations and places. This principle works in the same way as when a new mother is out shopping and hears a baby cry and looks down to see that her blouse has wet spots from a spontaneous milk ejection.