The SARS-CoV-2 pandemic leads to restrictions and changes, not only in terms of limitations on social contacts and activities, but also in the health care system, which particularly affects expectant parents and their unborn children (e.g., changes in the health care system, social distancing, lack of social support). Maternal stress in the peripartal period has a negative impact on child development as well as on the mother-child relationship, especially if the expectant mothers are additionally psychologically stressed. The study will therefore examine behavioral, hormonal, and clinical psychological correlates of stress in a multimethod approach (ecological momentary assessment (EMA) as well as laboratory studies) from pregnancy to one year postpartum at four measurement time points in a sample of N = 194 expectant mothers and their partners. Infant socio-emotional and cognitive development will be assessed with standardized developmental tests and tasks at 9 and 12 months of age. Special focus will be placed on the quality of mother-child interaction at 9 months of age as a mediator between maternal stress and child development. In the interdisciplinary part of the project, semi-automated coding systems for the evaluation of mother-infant interaction will be evaluated. Aims of the study are:

• (1) To examine the association between maternal stress during pregnancy and postpartum during the SARS-CoV-2 pandemic on child development.
• (2) To examine whether the SARS-CoV-2 pandemic alters maternal stress levels during pregnancy and postpartum, as well as the quality of the mother-child relationship during the child's first year of life (comparison with a sample from a study conducted before the outbreak of the SARS-CoV-2 pandemic).
• (3) Development and integration of a new semi-automated multimodal behavioral analysis software tool with the goal of making AI methods available for evaluating standardized interaction paradigms, and comparison with two analogous, reliable evaluation methods. A better understanding of how stress in pregnancy and the postpartum period affects child development is urgently needed. The foundation for socio-emotional competencies, and stress regulation skills in particular, is laid early in life. The planned study will contribute to a better understanding of the exact relationships.