Roseriet Beijers

Introduction The transition to parenthood is often accompanied by maternal psychological distress (i.e., symptoms of depression, anxiety, and stress) (Dipietro, Costigan, & Sipsma, 2008; Monk et al., 2022). During pregnancy, increased maternal distress predicts poorer infant outcomes, including compromised neurodevelopment and increased negative affect, via various physiological mechanisms (Beijers, Buitelaar, & de Weerth, 2014; Van den Bergh et al., 2020).

1 INTRODUCTION Depression is one of the most prevalent and debilitating conditions during the perinatal period, affecting 20% of perinatal women (Yin et al., 2021). Sleep disturbances are also common during the perinatal period, with 90% of women reporting disruptions in their sleep (Christian et al., 2019).

1 INTRODUCTION When a stimulus is presented to an infant multiple times, the time they spend looking at it will gradually decrease. Once a novel stimulus is presented, the infant will look at it for a longer amount of time compared to the previous stimulus. These two phenomena are called habituation and dishabituation, respectively.