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Let-Down Reflex (Milk Ejection Reflex)

What is the let-down reflex?

When you breast-feed, your baby's sucking stimulates nerves in your nipple. These nerves carry a message to your brain, and a hormone, called oxytocin, is released. Oxytocin flows through your bloodstream to your breasts, where it causes tiny muscle cells around your milk glands to squeeze milk out of the glands and into the milk ducts. This is known as the let-down reflex or the milk ejection reflex.

Once your let-down is working well (usually by 2 weeks after delivery), you may feel a pins-and-needles or tingling sensation in your breasts when you nurse or pump. Milk usually will drip from one breast while you are feeding on the other side. Sometimes your let-down will occur when you hear your baby cry or think about nursing your baby. A well-functioning let-down reflex helps ensure your breasts get well-drained and your baby easily gets milk.

Sometimes a woman's let-down reflex doesn't work as well as it should. This can make it hard for your baby to get milk when breast-feeding or for you to remove milk easily with a breast pump.

What causes a poor let-down reflex?

Several situations may prevent the let-down reflex from working well.

  • You may have severely sore nipples that cause you to tense up before each nursing.
  • You may be stressed, anxious, or tense. For example, you may be trying to pump breast milk during a short break at work.
  • You may be separated from your baby. For example, if you have to pump at home while your premature baby is still in the hospital.
  • You may have had a previous breast surgery that has damaged the normal nerve pathways to the nipple, such as breast reduction or enlargement surgery. If your nipple is either somewhat numb or very sensitive, it is possible that nerve damage from the procedure could interfere with your let-down reflex.
  • Cigarette smoking interferes with the let down reflex.

What can I do to improve my milk flow?

The following suggestions can help trigger the let-down reflex and improve milk flow:

  • Try to nurse or pump in a place that is familiar, comfortable, and restful.
  • Drink a beverage such as water or herbal tea whenever you sit down to nurse or pump.
  • Play soft music or do relaxation exercises before you nurse or pump.
  • Gently massage your breasts before you nurse or pump.
  • Have your partner give you a backrub before you nurse or pump.
  • Put a warm washcloth or heating pad on your breasts, or take a warm shower before you nurse or pump.
  • If you are pumping because you are separated from your baby, put a photograph of your baby by the pump.

Are there medical alternatives to improve my milk flow?

Oxytocin is a hormone that women's bodies make during pregnancy and breast-feeding. Mothers of premature infants or working mothers who need help conditioning their let down reflex when using a breast pump may be prescribed oxytocin nasal spray. This is a synthetic (man-made) form of the drug. A compounding pharmacy can prepare this drug with a prescription from your healthcare provider. Oxytocin usually is needed for only 2 or 3 days before your let-down reflex improves.

Written by Marianne Neifert, MD, and the clinical staff of The Lactation Program, Rose Medical Center, Denver, CO. 303-377-3016.
Published by RelayHealth.
Last modified: 2009-01-09
Last reviewed: 2009-11-22
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
2010 RelayHealth and/or its affiliates. All Rights Reserved.
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