Getting a good night's sleep is nearly impossible as a new parent, but navigating through conflicting information on how infant feeding choices affect sleep patterns can make it even more complicated.
There's quite a bit of conflicting information about whether formula feeding or breastfeeding is better for infant sleep, as well as how it can affect the mother's rest. From anecdotal stories about babies sleeping better once they switched to formula to breastfeeding advocates saying that breastfed babies sleep better, it can be hard to know what to trust. So what does the scientific research say?
First, it's important to understand how babies tend to eat and sleep. Most infants under the age of six months don't sleep through the night, but each individual can vary and still be healthy and happy. Some babies get hungry every hour or so, while others may sleep for up to five hours before they wake up wanting to be fed.
Babies also eat in different amounts. Newborns may only take a couple of sips at a time and then feel full, while others may be comfortable consuming larger amounts in each feeding. The amount your baby will drink at each meal gradually increases over time as well. On average, newborn babies who are exclusively breastfed typically eat every two to four hours, while babies who are formula-fed often eat every two to three hours.
Because of these variations in eating habits, there are no hard-and-fast rules about how long a baby should stay asleep at night. Newborns typically sleep for 16 to 18 hours a day, although that gradually decreases over time as the baby grows. However, some babies may sleep more, while others may sleep less. If you're concerned about how much your baby is eating or sleeping, contact your doctor for advice.
Overall, most studies show that infant feeding methods don't have a significant effect on infants' sleep patterns before six months of age. Breastfeeding may have a slight beneficial effect on mothers, but it depends on the sleeping setup and other factors. However, the infants' sleep duration seems to be fairly similar regardless of whether the baby is exclusively breastfed, exclusively formula-fed or fed using both methods.
Research in infants aged 6 to 11 months is slightly less clear, although studies still tend to show that the choice of formula or breastfeeding doesn't seem to have a significant impact on whether an infant sleeps through the night.
Another concern of many parents is whether breastfeeding or formula feeding can help reduce the risk of sudden infant death syndrome, or SIDS, which is a problem that may be related to sleep habits. Some evidence does indicate that breastfeeding may help reduce the risk, but other studies contradict that and show no difference in the risk for formula-fed babies. Studies on arousability, which means how easily a baby can be awakened, don't show a correlation between formula-fed infants and breastfed infants.
While there may be no real difference in how formula-fed and breastfed babies sleep, parents should think about some logistical considerations. Breastfeeding requires the mother to perform most or all feedings even if she's very tired, which can put the baby at risk if she falls asleep while feeding. Formula or mixed feeding methods can help both parents share the responsibility, although fatigue can still pose a risk to infants.
However, these problems can be avoided by practicing safe feeding practices, including:
Deciding how to feed your new baby is complicated, with no right or wrong answers. If you're struggling with the decision, rest assured that there's no strong evidence that either breastfeeding or formula feeding has a significant effect on infants' sleep cycles. While most professional organizations recommend breastfeeding as a general rule, your doctors and other medical professionals can help you choose the right strategy for your baby.
© 2020 American Sleep Association.