In the study, the researchers aim to investigate the impact of contact restrictions during the pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on newborns and their parents. At the onset of this COVID-19 pandemic, contact restrictions in Germany were introduced on March 16th, 2020. These included, among others, the ban on visits to hospitals. This also applied to visits by fathers of newborn children. In many hospitals, fathers were allowed to accompany the mother in the delivery room for birth, but had to leave the hospital before the mother was being transferred to the ward. Fathers were not allowed to visit their wives and newborns until discharge several days later.

The hypothesis of this study is that these contact restrictions have an influence on mother-infant interaction as well as on the psychological well-being of the parents. Furthermore, the investigators postulate that these restrictions additionally have a long-term effect on neonatal stress signaling pathways. For this purpose, children are studied, who were born during the period of strict contact restrictions from March, 16th to April, 30th, 2020. The children will be assessed at about six months of age.

Due to the COVID-19 pandemic in spring 2020, the German government decided to impose strict contact restrictions to prevent an exponential increase in SARS-CoV-2-positive individuals. These included visiting regulations in hospitals from March 16th, 2020. These also applied to obstetrics departments in Cologne until April 30th, 2020. At the Obstetrics University Hospital Cologne as well as at the Protestant Hospital Cologne-Weyertal, fathers were allowed to be present in the delivery room for the birth of their newborns, but had to leave the hospital again before the mothers were being transferred to the obstetrics ward. The fathers could not see their newborn again until they were discharged a few days later. The consequences of these contact restrictions on the newborns and their parents have been little studied.

In a few hospitals, there were exceptions currently to the strict contact restrictions. These included the Hospital of the Augustinian Sisters in Cologne, where no visitation bans were imposed on fathers in the obstetrics department. With general precautions fathers were still allowed to accompany their newborns and mothers in the obstetric ward. The study of the newborns of this hospital enables the researchers to see whether the parents were nevertheless affected by the general changes in the living situation during a pandemic.

The phenomenon of "neonatal programming", which establishes the connection between formative influences in the neonatal period (e.g. pain or stress by separation of mothers) and disorders in later life (attention deficits, lack of concentration, learning difficulties) has received increasing attention in recent years. In particular, the search for molecular mechanisms that cause such programming has been the focus of scientific projects. In a delivery-room skin-to-skin study (deisy) conducted by this research group preterm infants were randomized to skin-to-skin contact or visual contact with their mothers. Significant differences were found in both mother-infant interaction at six months of age and the expression of candidate genes of stress signaling pathway.

An important regulatory mechanism for influencing the activity of certain genes in the long term is the methylation of their promoter region. This epigenetic regulatory mechanism plays an important role, so that the modulation of DNA methylation by events in the neonatal period could be responsible for a permanent determination of a certain infant phenotype. This methylation in candidate genes in the stress signaling pathway is currently investigated by the research team in healthy mature neonates born before the onset of the pandemic, and results are pending.

The aim of the present study is to investigate the impact of contact restrictions during the coronavirus pandemic on newborns and their parents.

Normally in healthy mother-infant-dyads without separation during the first postpartal hours, the mother has the best conditions to develop a high level of sensitivity. Sensitive maternal behavior favors the formation of optimal mother-infant interaction and is relevant for infant neurocognitive development. Due to the stressful situation caused by the separation of the father for several days, the psychological well-being of the parents as well as the optimal mother-child interaction could be negatively affected.

Inclusion Criteria:

• birth from March, 16th, 2020 to April, 30th, 2020 with with subsequent stay for at least 48 hours in the obstetrics wards of the University Hospital of Cologne, the obstetrics department of the protestant hospital Köln-Weyertal or Hospital of Augustinian Sister's of Cologne
• mature newborn (38+0 to 41+6 weeks of gestational age)
• first child
• no separation of mother and child after birth
• informed consent
• good german language skills

Exclusion Criteria:

• multiples
• malformations or syndromes in the infant, reanimation after birth
• maternal psychological or severe physical illness

The study population consits of healthy mature newborns who were born during the time of strict contact restrictions from March, 16th to April, 30th, 2020. The recruitment will take place in three obstetric hospitals in Cologne (University Hospital of Cologne, Krankenhaus der Augustinnerinnen, evangelisches Krankenhaus Köln-Weyertal).