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 bottlefeeding (Blyton et al., 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. And 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.
The most recent study was published in the journal Sleep, a major sleep-medicine journal not necessarily known for its support of breastfeeding. This was a study of 2,830 women at 7 weeks postpartum (Dorheim et al., 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.
The results of these previous studies are remarkably consistent. Breastfeeding mothers are less tired and get more sleep than their formula- or mixed-feeding counterparts. And this lowers their risk for depression. Doan and colleagues 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.
Kathleen Kendall-Tackett, Ph.D., IBCLC is a health psychologist, board-certified lactation consultant, and La Leche League Leader. She is clinical associate professor of pediatrics at Texas Tech University School of Medicine in Amarillo, Texas.
1. 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.
2. 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.
3. 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.
4. 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.
5. 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.