Exploring the sleep of young children in Aotearoa New Zealand : associations with ethnicity and maternal depression in and beyond the perinatal period : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Clinical Psychology at Massey University, Wellington, New Zealand

Abstract

Sleep plays a vital role in children’s health. Sleep development is influenced by a complex interplay of biopsychosocial factors. There is emerging evidence to suggest perinatal depression (PND) is one such factor, but further investigation is needed. In Aotearoa/New Zealand, ethnic inequities in the social determinants of health produce sleep health disparities that are evident from preschool age through adulthood; it is currently unclear whether they exist in infants. To address these research gaps, secondary data from the Moe Kura: Mother and Child, Sleep and Wellbeing in Aotearoa/New Zealand study (Moe Kura) were analysed in two studies. Kaupapa Māori research principles informed the study designs.

First, sleep health equity, socio-ecological factors associated with infant sleep, and the characteristics of mother-perceived infant sleep problems were investigated using data from 383 Māori and 702 non-Māori mother-infant dyads at 12 weeks postpartum. Next, longitudinal relationships between maternal depression and infant and preschooler sleep health in 262 Māori and 594 non-Māori dyads were examined using data collected during pregnancy, 12 weeks postpartum, and 3 years post-birth. Multivariable and ordinal logistic models assessed the impact of different socio-ecological factors on infant sleep. Binary logistic models examined longitudinal associations between PND and infant and preschooler sleep, adjusting for key socio-demographic variables.

Key developmental markers of infant sleep did not differ by maternal ethnicity. There were some ethnicity-based differences in sleep location. Bed-sharing and several socio-demographic factors were related to different dimensions of infant sleep and mother-perceived sleep problems. Bivariate associations were found between prior and concurrent depressive symptomology and many of the infant and preschooler sleep outcomes. Prenatal depressive symptoms remained independently associated with shorter-than-recommended sleep durations in preschoolers after controlling for key covariates.

Results show sleep at 12 weeks is highly variable and is associated with numerous socio-ecological factors. Sleep appears to be one pathway by which PND confers risk for poor child health outcomes. Findings support the need for more and better perinatal psychological services.