Hush-a-by mummy: interactions between co-sleeping and maternal sleep disturban ce Ashleigh Filtness*, Janelle Mackenzie, Kerry Armstrong CARRS-Q, Queensland University of Technology, Queensland, Australia CRICOS No J Summary: In relation to other sub-populations vulnerable to sleep loss (e.g. shift workers) sleep in new mothers is comparably under investigated. At postpartum weeks 6, 12 and 18 the quantity of sleep new mothers obtain is consistent (≈7h), as are the frequency of night time wakings. Sleep disturbance reduces over time, as the duration of time awake per night time waking reduces. Mothers co-sleeping with their infant reported greater disturbance to their sleep and great ESS during weeks 6 and 12 than those who did not co-sleep, these differences are not apparent by week 18. Introduction Childbirth is an extraordinary, everyday experience; in 2011, infants were born in Australia [1], resulting in countless potential occurrences of sleep disturbance and subsequent daytime sleepiness. While the relationship between sleep and sleepiness has been heavily investigated in the vulnerable sub-populations of shift workers and patients with sleep disorders, comparatively postpartum women have been overlooked. Previous research has reported slower reaction times to the Psychomotor Vigilance Task [2] and shorter sleep onset in the multiple sleep latency test [3] in new mothers compared with control women. However little is known about change in sleep and sleepiness over time or potential interactions with infant care behaviour choices, such as co- sleeping (mother and infant sharing a bed). This study aims to investigate change in new mothers sleep quantity, sleep quality and resulting daytime sleepiness over postpartum weeks 6, 12 and 18, while evaluating the impact of co-sleeping. References: [1] Australian Bureau of Statistics (2011) "Births, Summary statistics for Australia." Accessed 1/7/13. [2] Insana, Salvatore P, Kayla B Williams and Hawley E Montgomery-Downs "Sleep disturbance and neurobehavioral performance among postpartum women." Sleep 36 (1): [3] Insana, Salvatore P and Hawley E Montgomery‐Downs "Sleep and sleepiness among first‐time postpartum parents: A field‐and laboratory‐based multimethod assessment." Developmental Psychobiology.. Method Participants: Thirty three new mothers, mean age 30.0 years (SD 4.0) free from psychiatric or medical problems, including postpartum depression. Protocol: Participants prospectively recorded every episode of sleep and wake (themselves and their infant) including sleep location during the 168 hours of postpartum weeks 6, 12 and 18, in 15 minute epochs. Participants chose their own sleeping arrangements. Nocturnal sleep period was considered to be made up of recurrent sleep episodes whereby any intermittent wake periods were shorter than the subsequent sleep episode. Sleep measures: Total nocturnal sleep time (TST), number of nocturnal wake episodes, sleep disturbance index (SDI; = (WASO / nocturnal sleep period)*100). Sleepiness measures: Subjective sleepiness was reported using the Epworth Sleepiness Scale (ESS), completed once per study week. Analysis: Data for all measures were analysed using mixed measures ANOVA with the within-subjects factors of Time (3 levels: week 6, week 12, and week 18) and the between subjects factors of Group (2 levels: no co-sleeping and co-sleeping). Post-hoc pairwise comparisons were conducted using Bonferroni tests Results Conclusion Daytime sleepiness in new mothers can reach clinically dangerous levels. Excessive daytime sleepiness (EDS; ESS >12) was common; 66.7% of participants in week 6 and 60.6% of participants in week 12. A clinician faced with a patient with an 18 week history of EDS would likely offer advice and information regarding implications for daytime impairment (e.g. when driving), yet little is known about the implications for EDS in otherwise healthy postpartum women. Considering that sleep quantity and frequency of night time wakings remained consistent, daytime sleepiness appears to be driven by the duration of the sleep disturbances. The reduction of SDI and consistent number of wakings over time suggest improved efficiency by mothers at settling their infant back to sleep. Although ESS and SDI decreased over time the reduction occurred earlier for those choosing not to co-sleep, demonstrating the impact of infant care choices. Participants dictated their own sleeping arrangement; the majority of mothers choose not to co-sleep. Consequently, current results should be considered preliminary. Future research with postpartum mothers may wish to consider a recruitment strategy based on intentions to co-sleep or not. These results are important as they quantify the excessive level of sleepiness experienced by the new mothers. Healthcare providers advising new mothers should consider the potential influence of co-sleeping on the dynamic changes to sleep and sleepiness during the initial postpartum period. Figure 1: Epworth sleepiness score with standard error barsFigure 2: Night time sleep (left axis) and number of wakings (right axis) with standard error bars Figure 3: Sleep disturbance index with standard error bars Epworth Sleepiness Scale There was a significant group by time interaction [F(2,62)=10.04, p< 0.001], daytime sleepiness being greater for co-sleepers (n =6) during weeks 6 and 12. Overall, ESS reduced over time [F(2,62)=30.07, p< 0.001]. Night time sleep Number of minutes sleep obtained did not change across time points [F(2,62)=0.19, p = 0.824] nor did number of night time wakings [F(2,62)= 1.02, p = 0.366]. There was no interacting effect of co- sleeping. Sleep disturbance index There was a significant group by time interaction [F(2,54.51)=3.73, p = 0.035], sleep disturbance being greater for co-sleepers (n = 6) during weeks 6 and 12. Overall, SDI reduced over time [F(2,54.51)=18.82 p< 0.001].