What is letdown (milk ejection) reflex and what causes it?
Take a look at the mechanism of breast milk production and secretion.
Breast milk is released when the baby sucks on the nipple. It may not work at first, as both baby and mother are beginners, but with repetition, both will grow more adept at it.
Mechanism of breastmilk secretion
The acinar is composed of a large number of acinar cells.
Breast milk is produced in acinar cells, and secreted inside the acinar. It is released from the body through breast ducts. Myoepithelial cells around the acinar contract like a pump to discharge the breast milk.
The let-down reflex
The hormone oxytocin causes the cells around the alveoli to contract and eject milk down the ducts and this passing of the milk down the ducts is called ''let-down'' (milk ejection) reflex.
- Let-down is experienced in numerous ways including:
- Your infant begins to actively suck and swallow.
- Milk may drip from the opposite breast.
- You may feel a tingling or a full sensation (after the first week of nursing) in your breasts or uterine cramping.
- You may feel thirsty.
NOTE: There may be many let-downs during a feeding, of which you may or may not notice. Because the brain plays such a large role in the release of hormones that cause the milk to eject, it is very normal for let-downs to occur in other situations as well. For example, let-down may occur when you think about your baby, hear your or another baby cry, when it is your scheduled nursing time, when you are sexually stimulated or during orgasm.
If the let-down occurs at an awkward time, cross your arms over your chest, or press the heel of your hand over the nipple area and apply pressure until the leaking stops. It may also help to wear cotton breast pads (without plastic liners) in your bra to protect your clothing, especially during the first weeks. This type of response will usually lessen after the first few weeks of nursing.
Uterus response postpartum
Release of the oxytocin hormone while breastfeeding will also cause the uterus to contract. This may be more noticeable if you have previously had children. This mechanism helps your uterus return to its pre-pregnancy size quickly.
Interference with let-down
A variety of factors may interfere with let-down:
- Emotions such as embarrassment, anger, irritation, fear or resentment
- Poor suckling from improper positioning
- Not enough time baby is actively nursing
- Negative remarks from relatives or friends
- Pain in your breasts or uterus (i.e., sore nipples or afterbirth pains)
- Breast engorgement in the first few days