Nov. 9, 2010 -- New mothers who breastfeed their infants don't lose any more sleep than their formula-feeding counterparts, according to a new study.
Researchers found that women who breastfed their newborns got as much sleep during the night and were neither more nor less tired during the day than new mothers who formula fed their infants or used a combination of the two.
"Although the benefits of breastfeeding are undisputed, mothers' concerns about how feeding methods might affect their sleep are legitimate," write researcher Hawley E. Montgomery-Downs, PhD, of West Virginia University, and colleagues in Pediatrics. "Mothers should be given the most current evidence to help them make decisions regarding feeding methods."
"Specifically, women should be told that choosing to formula feed does not equate with improved sleep," they write.
Researchers say previous research on the impact of formula vs. breastfeeding on mother's sleep has produced mixed results. One study showed breastfeeding mothers spent more time awake during the night but got the same amount of sleep as their formula-feeding peers. Another study showed breastfeeding moms slept about 40 minutes more but woke more than mothers who formula fed their infants.
In this study, 80 new mothers kept daily sleep diaries and wore devices that measured nighttime sleep for 10 weeks starting 2 weeks after birth.
Researchers measured total sleep time, total time spent awake during the night, sleep quality, fatigue, and daytime sleepiness.
The results showed no differences in total sleeping time or sleep quality between mothers who were exclusively breastfeeding, exclusively formula feeding, or using a combination of the two.
In addition, there were no differences in fatigue and daytime sleepiness.
Researchers say if breastfeeding mothers are waking more often at night, they may return to sleep more quickly and not remember these awakenings.
"Possible explanations for this may include the fact that they are not exposed to as much ambient light or physical activity, compared with preparing formula," write the researchers. "It is also possible that breastfeeding mothers sleep during feedings."