Oxytocin and Breastfeeding

The Hormone Responsible for Love, Bonding, and Let-Down

Woman napping with her baby

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Oxytocin is a hormone produced by the pituitary gland in the brain. It has many functions in the human body. It increases relaxation, lowers stress and anxiety, lowers blood pressure, and causes muscle contractions. Oxytocin is also the hormone involved in social relationships, bonding, trust, and love.

Oxytocin is an important hormone for women. During childbirth, oxytocin causes the uterus to contract and push out the baby. It's also involved in orgasm, and it plays a pivotal role in breastfeeding. Oxytocin is also known as the mothering hormone, the anti-stress hormone, and the love hormone.

The Link Between Oxytocin and Breastfeeding

Breastfeeding stimulates the release of oxytocin from your brain. Oxytocin allows your baby to get breast milk from your breasts, and it causes your uterus to shrink down after the birth of your baby. It also fosters love, nurturing, and a strong emotional bond between you and your child.

The release of oxytocin while you're breastfeeding may make you feel sleepy and relaxed. It can raise your body temperature so you may feel hot while you're nursing. It might also make you feel thirsty, ore even give you a headache.

Oxytocin and the Let-Down Reflex

When your baby latches on to breastfeed, and their mouth touches your breasts, especially your nipples, the nerve cells in your breasts send a signal to your brain to release oxytocin. The oxytocin causes the muscles around the milk-making glands in your breast to contract.

When the glands contract, they squeeze the breast milk into the milk ducts. The milk ducts also contract to push the breast milk through your breast, and out of the nipple to your baby. This release of breast milk is called the let-down reflex. As your baby continues to breastfeed, more oxytocin is released, and breast milk continues to flow out of your breasts and to your baby.

Oxytocin can also cause your milk to let down when you're not breastfeeding. You may find that your breasts leak breast milk when you think about breastfeeding or hear your baby cry.

While oxytocin is responsible for the let-down reflex and the release of breast milk from your body, it has nothing to do with the amount of breast milk that you will make. The hormone related to the production of breast milk is called prolactin.

Signs That Your Body Is Releasing Oxytocin

How can you tell if the oxytocin in your body is doing what it's supposed to do? Here are some of the signs you can look for:

  • A tingling or a pins-and-needles sensation in your breasts
  • Cramping in your uterus when you breastfeed
  • Hearing your baby swallow while you're breastfeeding
  • Seeing breast milk leaking from your breasts
  • Feeling happy and relaxed after you feed your baby

Oxytocin and After Pains

When your baby is breastfeeding, and oxytocin is released, it triggers contractions of the uterus. These uterine contractions are often called after pains and they feel similar to menstrual cramps.

In the first few days after childbirth, after pains can be very strong and, as the name suggests, painful. But these uterine contractions help to lessen the amount of postpartum bleeding and prevent hemorrhage. They also allow the uterus to shrink back down to its normal, not-pregnant size more quickly.

Oxytocin and a New Pregnancy

Breastfeeding during a new pregnancy is usually safe. However, since oxytocin, can cause contractions, breastfeeding during a high-risk pregnancy may not be recommended. If you're carrying twins or more, or have a history of premature labor, your doctor may advise you to avoid breastfeeding to prevent labor from starting too soon.

Oxytocin is also released during physical intimacy and orgasm. If you have a high-risk pregnancy, sex can also cause uterine contractions and premature labor. If your doctor advises you against breastfeeding, she may also ask you to avoid a physical relationship with your partner, as well.

Problems With the Release of Oxytocin

Some conditions can interfere with the release of oxytocin. These might cause difficulty with breastfeeding.

If you are in pain after the birth of your baby, especially if you've had a c-section, the pain could interfere with the release of oxytocin. If you're in pain, you should take the pain medication that your doctor has prescribed for you. It may make your baby a little sleepy, but it will help you to feel more comfortable and get breastfeeding off to the right start.

Any breast surgery that involves moving the areola or cutting the nerves around the nipple can be problematic for breastfeeding. The nerves in the nipple are needed to signal your brain to release the oxytocin and get your milk flowing. Any nerve damage in that area could interfere with let-down reflex and the removal of the milk from your breasts.

Stress, fatigue, illness, fear, embarrassment, drinking alcohol, and smoking can all affect the release of oxytocin, interfere with your let-down reflex, and keep your baby from getting the breast milk from your body.

Oxytocin Nasal Spray

Pitocin is an artificial form of the natural hormone oxytocin. For women who have difficulty getting their milk to let down, a doctor can prescribe oxytocin (Pitocin) nasal spray. It is taken right before breastfeeding or pumping to help bring about let-down and get the breast milk flowing. It can cause headaches for a mother, but it does not affect the baby or breast milk.

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Article Sources
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  2. Infant and Young Child Feeding: Model Chapter for Textbooks for Medical Students and Allied Health Professionals. World Health Organization; 2009.

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Additional Reading
  • Cadwell K, Turner-Maffei C, O'Connor B, Cadwell Blair A, Arnold LDW, Blair EM. Maternal and Infant Assessment for Breastfeeding and Human Lactation A Guide for the Practitioner Second Edition. Jones and Bartlett Publishers, 2006.

  • Lawrence RA, Lawrence RM. Breastfeeding A Guide For The Medical Profession Seventh Edition. Mosby, 2011.

  • Riordan J, Wambach K. Breastfeeding and Human Lactation Fourth Edition. Jones and Bartlett Learning, 2014.