Maternal pandemic-related stress during pregnancy associates with infants' socio-cognitive development at 12 months: A longitudinal multi-centric study

Background: Prenatal maternal stress is a key risk factor for infants' development. Previous research has highlighted consequences for infants' socio-emotional and cognitive outcomes, but less is known for what regards socio-cognitive development. In this study, we report on the effects of maternal prenatal stress related to the COVID-19 pandemic on 12-month-old infants' behavioral markers of socio-cognitive development. Methods: Ninety infants and their mothers provided complete longitudinal data from birth to 12 months. At birth, mothers reported on pandemic-related stress during pregnancy. At infants' 12-month-age, a remote mother-infant interaction was videotaped: after an initial 2-min face-to-face episode, the experimenter remotely played a series of four auditory stimuli (2 human and 2 non-human sounds). The auditory stimuli sequence was counterbalanced among participants and each sound was repeated three times every 10 seconds (Exposure, 30 seconds) while mothers were instructed not to interact with their infants and to display a neutral still-face expression. Infants' orienting, communication, and pointing toward the auditory source was coded micro-analytically and a socio-cognitive score (SCS) was obtained by means of a principal component analysis. Results: Infants equally oriented to human and non-human auditory stimuli. All infants oriented toward the sound during the Exposure episode, 80% exhibited any communication directed to the auditory source, and 48% showed at least one pointing toward the sound. Mothers who reported greater prenatal pandemic-related stress had infants with higher probability of showing no communication, t = 2.14 (p = .035), or pointing, t = 1.93 (p = .057). A significant and negative linear association was found between maternal prenatal pandemic-related stress and infants' SCS at 12 months, R2 = .07 (p = .010), while adjusting for potential confounders. Conclusions: This study suggests that prenatal maternal stress during the COVID-19 pandemic might have increased the risk of an altered socio-cognitive development in infants as assessed through an observational paradigm at 12 months. Special preventive attention should be devoted to infants born during the pandemic.