My son kicks off the covers and rouses from his slumber with a start. It’s 2am and he’s having a bad dream. He tugs at my pyjama top. He nurses, finds comfort, relaxes and falls back to sleep.
As the weight of his little body melts into my arms, I’m transported back in time to the early days of motherhood; sitting upright in bed with a nursing pillow around my waist, lamp on, snack handy and feeling mesmerized by the newborn spirit that nestled himself so quickly into my heart.
Yet, I also remember being told that by nursing my baby to sleep that I was creating “a rod for my own back”. I remember the mantra “feed, play, sleep”. I remember experts quoting random timeframes by which babies shouldn’t need to nurse through the night. I remember lying in the dark and googling “is nursing my baby to sleep a ‘bad sleep association?’” as I doubted myself and my instincts.
But my experience of breastfeeding and comforting my son to sleep – through baby and toddlerhood – has been anything but a bad habit. Nursing at night has been a natural gateway between our mellow slumber and the electric energy of our days. It keeps our nights peaceful. It gives me a few moments to reset and catch my breath after the busyness of our days. It has given me as much as it has given him and I wouldn’t change it for the world.
The further I have ventured into motherhood, the more I have learned that nature and science tend to tell the same story; that no matter what our society may say, breastfeeding and sleep are inextricably linked. As Dr. James McKenna of the Mother-Baby Behavioral Sleep Laboratory at The University of Notre Dame says, we are breastsleepers.
We are designed to nurse our babies to sleep however long it is mutually necessary and enjoyable.
So, if you like me, are being told mistruths about the incredible gift of nighttime breastfeeding, I want to put your mind at ease so that you don’t waste time and energy looking over your shoulder and instead spend that time enjoying your motherhood. Let’s dig deeper into the science of nighttime parenting and how mother nature gives us the power to help our babies find sleep.
1. Nighttime breastmilk helps babies fall and stay asleep.
Babies are born without established circadian rhythms. What is a circadian rhythm? The term circadian comes from the Latin circa, meaning “around” (or “approximately”), and diēm, meaning “day”. So, a circadian rhythm is a roughly 24-hour cycle that helps regulate the time we are awake to be during daylight hours and the time we are asleep to be during nighttime hours.
Our circadian rhythms are under the control of a number of different hormones. Perhaps the most well-known sleep hormone is melatonin. When the sun goes down melatonin levels rise and make us feel sleepy. But, the pineal gland, the area of the brain responsible for producing melatonin, is immature at birth. Research on the development of circadian rhythms has concluded that sleep-related circadian rhythms do not begin to emerge until the eighth week after birth. (1) Further research indicates that circadian rhythms are not well established until babies are around four months of age and not mature until one year of age. (2,3)
This means that young babies can’t tell night from day and no matter what we do, the development of circadian rhythms is a developmental milestone that cannot be rushed.
However, mother nature is wise and she designed us to be synchronous with our babies, so while babies cannot produce their own melatonin, nighttime breastmilk is a rich source of melatonin. Nighttime breastmilk contains substantial amounts of melatonin, whereas daytime levels are undetectable. This is one of the miraculous reasons that nighttime breastmilk helps babies fall (and stay) asleep. (4)
2. Nighttime breastmilk is different to daytime breastmilk (and carries unique benefits)
In addition to melatonin, nighttime breastmilk is rich in other sleep-inducing and brain-boosting substances. Darcia Narvaez, PhD, Early Childhood Researcher of the University of Notre Dame says: “Parents should know that breastmilk in the evening contains more tryptophan (a sleep-inducing amino acid). Tryptophan is a precursor to serotonin, a vital hormone for brain function and development. In early life, tryptophan ingestion leads to more serotonin receptor development. Nighttime breastmilk also has amino acids that promote serotonin synthesis. Serotonin makes the brain work better, keeps one in a good mood, and helps with sleep-wake cycles. So, it may be especially important for children to have evening or night breastmilk because it has tryptophan in it, for reasons beyond getting them to sleep.” (5)
3. Nighttime breastfeeding helps establish milk supply
Prolactin is a hormone that helps establish, build and maintain milk supply and it, like melatonin, also follows a circadian rhythm. In the early weeks of breastfeeding, the body lays down prolactin receptors in the breasts to help regulate milk production. Prolactin levels rise with suckling; the more a baby nurses, the higher prolactin levels rise and the higher a mother’s milk supply. Prolactin levels are significantly higher in nighttime breastmilk, particularly in the early hours of the morning; when a baby nurses at night he is helping his mother to establish a strong milk supply. (6) Babies may also nurse more at night because quite simply, there’s more milk at night.
4. Nighttime nursing may protect against colic
Infant colic, for which there is no known cure, typically affects babies between the ages of two weeks and four months and is characterized by crying episodes that generally occur in the evenings. While melatonin doesn’t follow a circadian rhythm at this age, another hormone, serotonin does. Melatonin and serotonin have a yin and yang type relationship, balancing one another out within the body. Serotonin reaches peak concentration in the evening and, when unopposed by melatonin, causes intestinal contractions. Melatonin relaxes the smooth muscle of the gastrointestinal tract, therefore reducing the risk of colic, but babies don’t produce melatonin until around three months of age. Unless there is an external source of melatonin, as there is in a mother’s breastmilk, colic becomes more likely. Young babies rely on nighttime breastmilk to provide the necessary melatonin to harmonize their physiology and protect against colic. (7,8)
5. Nighttime breastfeeding protects against SIDS
In a meta-analysis of 288 studies with data on breastfeeding and SIDS, it was found that “breastfeeding is protective against SIDS, and this effect is stronger when breastfeeding is exclusive.” It is thought that infant arousals help to keep babies in lighter, more protective stages of sleep, which may be protective against SIDS. These arousals are more frequent in babies who breastfeed through the night. The National Health and Medical Research Council in Australia reports that breastfeeding at night time may decrease the risk of SIDS by 44%. (9)
Mama, your nighttime parenting is yours to define
No mother should ever be made to feel as though she needs to justify the choices she makes to nourish her baby, day or night. Some mothers simply cannot or choose not to breastfeed for any number of valid reasons and there should never be any judgment around that.
But, for those mothers who do want to and are able to nurse their babies to sleep and through the night, there should be nothing but unconditional support and encouragement from family and friends. Other people do not have the right to pass judgment, to question or invalidate a mother’s choice for how she parents through the night. For how she uses HER body to nourish and nurture HER baby through the night.
Because the truth is that breastfeeding is an invaluable nighttime parenting tool. Without it we are left with a void that western culture tries to fill with artificial schedules, sleep training and isolation.
Babies are comfort seekers and attachment magnets.
They need to be close to their parents, especially during the night and if you choose to make breastfeeding a part of your shared experience be proud of your choice. The normalization of gentle nighttime parenting should not be interpreted as a rebellious act. We are social mammals with mammary glands that don’t put up a closed sign when the sun goes down.
Follow your heart mama. Trust your baby. Lean into your inner knowing. You got this.
(Portions of this post are an excerpt from The Good Science Guides: Sleep Series. Guide 01: Breastfeeding. You can find the guides here).
1. Antonini, S. R., Jorge, S. M., Moreira, A. C., The emergence of salivary cortisol circadian rhythm and its relationship to sleep activity in preterm infants, Clinical Endocrinology, 52(4) (2000), pp. 423–6
2. Mirmiran, M., Maas, Y. G., Ariagno, R. L., Development of fetal and neonatal sleep and circadian rhythms, Sleep Med Rev., 7(4) (2003), pp. 321-34
3. McGraw, K., Hoffmann, R., Harker, C., Herman, J. H., The development of circadian rhythms in a human infant, Sleep, 22(3) (1999), pp. 303–10
4. Rivkees SA, 2003. Developing circadian rhythmicity in infants. Pediatrics. 112(2):373-81
5. Dr. Darcia Narvaez, Psychology Today, Normal Infant Sleep: Night Nursing’s Importance
6. Riordan, J. & Wambach, K. (2010) Breastfeeding and Human Lactation 4th ed. Jones and Bartlett, Page 89
7. Cohen Engler A, Hadash A, Shehadeh N, Pillar G. 2012. Breastfeeding may improve nocturnal sleep and reduce infantile colic: potential role of breast milk melatonin. Eur J Pediatr. 171(4):729-32
8. L.Weissbluth, M.Weissbluth 1992 Infant colic: The effect of serotonin and melatonin circadian rhythms on the intestinal smooth muscle. Medical Hypotheses Volume 39, Issue 2, Pages 164-167
9. National Health and Medical Research Council (2012) Infant Feeding Guidelines. Information for Health Workers. Sourced March 7th 2019,