Nighttime Parenting and Infant Sleep

A. Researchers describe 2 primary sleep states:

1. Active (light sleep): increased blood flow to the brain, neural cells are stimulated - contributing to brain growth. Infants are easily awaken during active sleep, an ability important for baby's health and safety.
   
2. Quiet sleep (deep sleep): a restorative state important for saving up energy necessary for interacting and feeding when the infant is awake - contributing to memory development. It's more difficult to wake infants in quiet sleep.
   

B. Newborns sleep 16-17 hours per 24 hours, older infants sleep 13-14 hours/24 hours

1. Infants cycle through active sleep, quiet sleep and waking. Each cycle is about 60 minutes long and newborns wake with each cycle.
   
2. The percentage of total sleep spent in quiet sleep is about 50% (30 minutes) in newborns, 60% in 3-5 months old infant, up to 75% at 1 year of age.
   

C. What does it mean to parents of newborns and infants?

1. If external factors disturb the infant during light sleep such as phone ringing, TV, light and other sounds, or being put down into a bassinet or crib, they are more likely to wake! To break the cycle of repeated awakenings, parents can hold their baby for 20-30 minutes till they enter a deeper sleep state before putting them down.
   
2. Infants sensitive to light and sounds spend more needed energy trying to shut out external stimuli during sleep. They could have saved this energy for growth and development instead.
   
3. Night waking may be essential for young infant's and parents' health:
   

• Signals parents about unmet needs, hunger (babies need calories for growth!), discomfort, temperature control, or pain from an illness, infection or injury.
  
• Very young infants who have longer quiet sleep are at higher risk for SID (because they can't rouse themselves up).
• Night waking is beneficial for breastfeeding parents, building and maintaining milk supply, reducing the risk of hormone-related cancers in parents.
  
• As infants get older, they need less adult assistance at night when they're physiologically ready to do so.

References:
Walker (2017) Breastfeeding Management for the Clinician