Most infants start sleeping through the night between the ages of 2 and 4 months, according to new research.

In the study, “Sleeping Through the Night: The Consolidation of Self-Regulated Sleep Across the First Year of Life,” published in the November issue of Pediatrics, parents of 75 normally developing infants completed sleep diaries for 6 days each month for 12 months. The accuracy of these reports was verified by a time-lapse video recorder.

The fastest consolidation in infant sleep regulation occurred in the first 4 months of life. During this time, infants were most likely to meet three different criteria for sleeping through the night (midnight to 5 AM, 8 hours, or 10 PM to 6 AM), and to have a mean longest self-regulated sleep period that exceeded 8 hours. Most infants were sleeping through the night at 2 and 3 months of age, regardless of the criterion used.

Prevention efforts should be focused in the first 3 months, beginning as early as 1 month for intervention to be in sync with the onset of sleeping through the night. Additional efforts are needed to determine the factors that precede and predict infant sleep issues.