Kathleen Kendall-Tackett, PhD, IBCLC, FAPA on preserving mothers’ mental health at nighttime.

Some professionals in perinatal mental health urge mothers to avoid nighttime breastfeeding so they can decrease their risk for postpartum depression. In fact, a whole cottage industry has sprung up with night nannies offering to handle nighttime care for mothers. We know that if mothers follow this advice, it will have a negative impact on breastfeeding. Mothers’ breasts need to be emptied on a regular basis to continue to make milk and avoid mastitis. Missing regular nighttime feedings will have an immediate and negative impact on milk production. But let’s put that issue aside for the moment and consider whether avoiding nighttime breastfeeding will preserve women’s mental health by allowing them to get more sleep. In short, is this good and necessary advice?

At first glance, it may seem to be. Since breast milk is lower in fat and protein than formula, we might assume, as I once did, that breastfeeding mothers sleep less than their formula-feeding counterparts. When a mother’s mental health is at stake, avoiding nighttime breastfeeding might be worth the risk it poses to breastfeeding. However, recent research has revealed the opposite and that breastfeeding mothers actually get more sleep, particularly when the baby is in proximity to the mother. That has major implications for their mental health. If you want one more good reason for mothers to exclusively breastfeed their babies, here it is: Breastfeeding Mothers Get More Sleep.

Should Mothers Avoid Nighttime Breastfeeding to Decrease their Risk of Depression?
Ken Tackett

How much sleep?

In a study of 33 mothers at 4 weeks postpartum, Quillin and Glenn (2004) found that mothers who were breastfeeding slept more than mothers who were bottle-feeding. Data were collected via questionnaire that recorded 5 days of mother and newborn sleep. When comparing whether bedsharing made a difference in total sleep, they found that bedsharing, breastfeeding mothers got the most sleep and breastfeeding mothers who were not bedsharing got the least amount of sleep. Mothers who were bottle-feeding got the same amount of sleep whether their babies were with them or in another room.

Sleep patterns of 72 couples were compared from pregnancy to the first month postpartum via sleep diaries and wrist actigraphy (Gay, Lee, & Lee, 2004). Most of the mothers were at least partially breastfeeding (94%) and 80% were exclusively breastfeeding. Most of the babies slept in their parents’ room and 51% regularly slept in their parents’ beds. Sleep and fatigue outcomes were not associated with type of birth, parent-infant bedsharing, or the baby’s age. Mothers who were exclusively breastfeeding had a greater number of nighttime wakings (30 vs. 24) compared with mothers who are not breastfeeding exclusively. The exclusively breastfeeding mothers slept approximately 20 minutes longer than mothers not exclusively breastfeeding.

Paula Modersohn-Becker 1876–1907

In a study of mothers and fathers at 3 months postpartum, data were collected via wrist actigraphy and sleep diaries (Doan, Gardiner, Gay, & Lee, 2007). The study compared sleep of exclusively breastfed infants vs. those supplemented with formula. In this sample, 67% were fed exclusively with breast milk, 23% were fed a combination of breast milk and formula, and 10% were exclusively formula-fed. Mothers who exclusively breastfed slept an average of 40 minutes longer than mothers who supplemented. Further, parents of formula-fed infants had more sleep disturbances. They concluded that parents who are supplementing with formula assuming that they are going to get more sleep should be encouraged to breastfeed so they will get an extra 30–45 minutes of sleep per night.

Not only do breastfeeding mothers get more sleep, the sleep they get is better quality. This study compared 12 exclusively breastfeeding women, 12 age-matched control women, and 7 women who were exclusively bottle-feeding (Blyton, Sullivan, & Edwards, 2002). They found that total sleep time and REM sleep time were similar in the three groups of women. The marked difference between the groups was in the amount of slow-wave sleep (SWS). The breastfeeding mothers got an average of 182 minutes of SWS. Women in the control group had an average of 86 minutes. The exclusively bottle-feeding women had an average of 63 minutes. Among the breastfeeding women, there was a compensatory reduction in light, non-REM sleep. Slow-wave sleep is an important marker of sleep quality, and those with a lower percentage of slow-wave sleep report more daytime fatigue and pain.

A study from the journal Sleep, a major sleep-medicine journal not necessarily known for its support of breastfeeding, included 2,830 women at 7 weeks postpartum (Dorheim, Bondevik, Eberhard-Gran, & Bjorvatn, 2009). The researchers found that disrupted sleep was a major risk factor for postpartum depression. But here is where it really gets interesting. When considering what disrupted sleep, they found that the following factors were related to disturbed sleep: depression, previous sleep problems, being a first-time mother, a younger or male infant, and not exclusively breastfeeding. In other words, mothers who were not exclusively breastfeeding had more disrupted sleep and a higher risk of depression.

These previous studies found that mothers who exclusively breastfed were the ones who got more sleep. We also found that, in our study of 6,410 new mothers in an online survey (Kendall-Tackett, Cong, & Hale, 2011). We found that exclusively breastfeeding mothers reported significantly more sleep and less daytime fatigue, fewer minutes to get to sleep, and better physical health.

Figure 1: Total number of hours mothers sleep

Should Mothers Avoid Nighttime Breastfeeding to Decrease their Risk of Depression?

Figure 2: Mothers’ report of their daily energy

Should Mothers Avoid Nighttime Breastfeeding to Decrease their Risk of Depression?

They also had significantly lower rates of depression, anxiety, and anger.

Figure 3: Mothers’ depression

Should Mothers Avoid Nighttime Breastfeeding to Decrease their Risk of Depression?

What surprised us was that there was no significant difference on any variable between mixed-feeding and exclusively formula-feeding mothers. This suggests that exclusive breastfeeding is physiologically different than mixed-feeding, and recommending that mothers supplement to get more sleep would likely prove counterproductive.


The results of these studies are remarkably consistent. Breastfeeding mothers are less tired and get more sleep than their formula- or mixed-feeding counterparts, which lowers their risk for depression. Doan and colleagues (2007) noted the following:

Using supplementation as a coping strategy for minimizing sleep loss can actually be detrimental because of its impact on prolactin hormone production and secretion. Maintenance of breastfeeding, as well as deep restorative sleep stages, may be greatly compromised for new mothers who cope with infant feedings by supplementing in an effort to get more sleep time (p. 201).

In sum, advising women to avoid nighttime breastfeeding to lessen their risk of depression is not medically sound. In fact, if women follow this advice, it may actually increase their risk of depression.


Blyton, D. M., Sullivan, C. E., & Edwards, N. (2002). Lactation is associated with an increase in slow-wave sleep in women. Journal of Sleep Research, 11(4), 297–303. doi:10.1046/j.1365-2869.2002.00315.x

Doan, T., Gardiner, A., Gay, C. L., & Lee, K. A. (2007). Breastfeeding increases sleep duration of new parents. Journal of Perinatal & Neonatal Nursing, 21(3), 200–206. doi:10.1097/01.jpn.0000285809.36398.1b

Dorheim, S. K., Bondevik, G. T., Eberhard-Gran, M., & Bjorvatn, B. (2009). Sleep and depression in postpartum women: A population-based study. Sleep, 32(7), 847–855. doi:10.1093/sleep/32.7.847

Gay, C. L., Lee, K. A., & Lee, S.-Y. (2004). Sleep patterns and fatigue in new mothers and fathers. Biological Nursing Research, 5(4), 311–318. doi:10.1177/1099800403262142

Kendall-Tackett, K. A., Cong, Z., & Hale, T. W. (2011). The effect of feeding method on sleep duration, maternal well-being, and postpartum depression. Clinical Lactation, 2(2), 22–26. doi:10.1891/215805311807011593

Quillin, S. I. M., & Glenn, L. L. (2004). Interaction between feeding method and co-sleeping on maternal-newborn sleep. Journal of Obstetric, Gynecologic and Neonatal Nursing, 33(5), 580–588. doi:10.1177/0884217504269013

Depression in New Mothers
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Kathleen Kendall-Tackett, PhD, IBCLC, FAPA

kathleen-kendall-tackett-womens-health-todayDr. Kendall-Tackett is a health psychologist and International Board Certified Lactation Consultant, and the owner and Editor-in-Chief of Praeclarus Press, a small press specializing in women’s health. She is Editor-in-Chief of two peer-reviewed journals: Clinical Lactation and Psychological Trauma. She is Fellow of the American Psychological Association in Health and Trauma Psychology, Past President of the APA Division of Trauma Psychology, and a member of the Board for the Advancement of Psychology in the Public Interest. Dr. Kendall-Tackett specializes in women’s health research including breastfeeding, depression, trauma, and health psychology, and has won many awards for her work including the 2016 Outstanding Service to the Field of Trauma Psychology from the American Psychological Association’s Division 56.

Dr. Kendall-Tackett has authored more than 400 articles or chapters, and has just completed her 35th book, The Phantom of the Opera: A Social History of the World’s Most Popular Musical. Her most recent books include: Depression in New Mothers, 3rd EditionWomen’s Mental Health Across the Lifespan with Lesia Ruglass, and The Science of Mother-Infant Sleep with Wendy Middlemiss. Her websites are:

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A Breastfeeding Friendly Approach to Depression