Background

The ability for infants to fall back asleep without parental involvement may reduce the frequency of night feeds and promote self-regulation; yet, few objective measures exist to quantify infant-only wake bouts. Using actigraphy, we describe infant-only wake bouts and their association with night feeds across the first 6 months of life.

Methods

Mother-father-infant triads (N=20) each wore sleep monitors for 1 week when infants were ages 6, 15, and 24 weeks. Data were time matched within-families to quantify infant-only wake bouts (e.g., infants were awake while mothers/fathers were asleep). For a subset of 2-3 days at each age, mothers were instructed to record infant feeds using a diary. Feeding mode (predominantly breastfed vs. not) and sleep location (in parents’ room vs. not) were collected via maternal report. Mixed models tested associations between infant-only wake bouts and night feed frequency, adjusting for feeding mode and sleep location.

Results

The proportion in the number of infant-only wake bouts per night, relative to total nighttime wake bouts, increased as infants aged (6 weeks: 45% [95% CI: 35-55]; 15 weeks: 65% [55-74]; 24 weeks: 60% [51-70]; p<0.01). The total number of feeds per night decreased as infants aged (6 weeks: 2.9 [2.3-3.5]; 15 weeks: 2.2 [1.6-2.8]; 24 weeks: 1.9 [1.3-2.5] feeds/night; p<0.01). Infant-only wake bouts early in life predicted change in feeds per night over time; for every 10% increase in the proportion of infant-only wake bouts per night at 6 weeks, there was a 1.4% [2.7%-0.2%] faster rate of decline each week in the number of feeds/night from 6 to 24 weeks (p=0.03).

Conclusions

Infants’ ability to fall back asleep without parent involvement at 6 weeks appears to influence the trajectory of nighttime feeding frequency across the first 6 months of life. Future research should explore this association using videosomography and nighttime feeding quantity.