Running title: Longitudinal study of infant sleep patterns

This study describes and compares the sleep patterns of parentally-perceived problematic and non-problematic infant sleepers aged 3 to 13 months. Parents of 63 infants completed brief infant sleep questionnaires (BISQ) and 7-day sleep diaries each month for up to 3 months. Problematic sleepers showed poorer sleep quality and quantity than their non-problematic counterparts over the 3-month period. For problematic sleepers, diaries indicated 1.3 ± 0.4 (mean ± SE) more night wakes per night (p=0.002), 0.92 ± 0.3 hours less total sleep over 24 hours (p=0.008), shorter sleep periods by 2.0 ± 0.7 hours (p=0.009), 0.54 ± 0.3 hours less night-time sleep (p=0.046) and more time awake between 2200 – 0600 by 0.27 ± 0.09 hours (p=0.05) and by 0.41 ± 0.1 hours (p=0.009) from BISQ. Expected developmental changes were observed in both groups, with day naps decreasing from 3.0 ± 0.1 to 2.5 ± 0.1 (p