Breast-Feeding: Let-Down 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 things may prevent the let-down reflex from working well.

  • You may have very 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 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.
  • Your healthcare provider can prescribe oxytocin nasal spray. This is a man-made form of a hormone that women's bodies make during pregnancy and breast-feeding. Oxytocin is usually only needed for only 2 or 3 days.

What is an overactive let-down reflex?

Some mothers have a forceful let down that causes too much milk to flow out of the breast too quickly. The mother may have sharp, shooting pain, and the baby may gulp, cough and sputter while feeding. Sometimes the baby may bite down on the nipple to decrease the flow, causing more pain. This most often happens within the first month of breastfeeding.

What can I do to decrease my milk flow?

  • Nurse your baby on just one breast per feeding to decrease supply a bit.
  • Do not stimulate your breasts by pumping them or taking long hot showers.
  • Put cool cloths on your breasts for 15 to 30 minutes between feedings.

To help baby deal with forceful let down:

  • Hold the baby upright, with his bottom much lower than his head. Support him in this position while he nurses.
  • Using the laid-back nursing position may help gravity to slow down the flow of milk so that your baby is able to tolerate the flow easier.
  • Burp your baby often if he swallows a lot of air.
  • Nurse your baby when he is relaxed and sleepy. His more gentle suckles will keep the milk from flowing so fast.
  • You can wait until let-down occurs, take your baby off the breast and allow the milk to collect in a towel or diaper.
  • You can hand express or pump your breasts through the first let-down to relieve the pressure, and then put your baby on your breast.

Written by Marianne Neifert, MD, and the clinical staff of The Lactation Program, Rose Medical Center, Denver, CO. 303-377-3016.
Published by RelayHealth.
© 2012 RelayHealth and/or its affiliates. All rights reserved.