Sleep & the Breastfed Baby, Part 1

Not only is it normal for a breastfed baby to night nurse, but it is also beneficial.

This is almost completely lost on our society that is used to bottle feeding patterns. Studies show that babies who sleep long stretches at night are at increased risk of Sudden Infant Death Syndrome (SIDS). They are more likely to get into a prolonged deep sleep and less likely to rouse out of it if their oxygen drops. The frequent night wakings of a healthy baby help increase arousals which keep babies in safe sleep states and help them recognize their own hunger. In fact, most of the safe sleep guidelines are oriented around helping babies sleep lightly and avoid prolonged periods of deep sleep. Breastmilk actually feeds the development of the part of the brain responsible for helping a baby wake up when there is danger.

Another reason formula fed babies eat less often at night is because its possible for caregivers to push larger volumes of milk in the daytime without the limitations of breast storage capacity or milk supply. In contrast, breastfed babies usually self-limit their feed size to 3-4 oz and therefore need night feeds to get enough food. Studies have found over and over again that the small frequent feeds of a breastfed baby lead to better health outcomes and prevent obesity. Most mothers and babies need 7-10 breastfeedings per 24 hours to sustain a full milk supply and growth, even beyond the newborn period, because feeding patterns are restricted by mom's milk storage capacity (see infographic). If there are long stretches between nursing sessions, the accumulating milk in mother's breasts signals her body to decrease production as the body thinks the unused milk was wasted energy expenditure.

It varies for every mother/baby pair, but the first month postpartum 8 feedings per 24 hour day with one 5 hour stretch seems to be a common tipping point before the signals to decrease supply are triggered. Interestingly, 5 hours is also the medical definition of sleeping through the night. 5 hours will get you from about 9pm to 2am. Interestingly, there is a surge of prolactin that mothers experience around 2am that results in a surge of milk production. Because of this, breastfeeds that occur around 1-3am are usually the biggest feed of the whole day and therefore go a long way to support infant growth and sustain milk supply. However if the 5 hour stretch is regularly exceeded, most women will experience a gradual decline in milk supply and struggle to achieve their personal breastfeeding goals. It may not always be immediately apparent, but after weeks or months of baby "sleeping through the night," mother may start to notice her supply and baby's weight percentiles have dropped to a concerning level. In fact, the so-called 4 month "sleep regression" is often a result of low milk supply and a caloric deficit after a period of baby sleeping through the night.