Continuous Delivery Room Skin-to-skin-study for Moderate and Late Preterm Infants (COSY)

DNA will be extracted from peripheral white blood cells and mucosal epithelial cells. The expression of candidate genes of the stress signaling pathways are investigated. The candidate genes are glucocorticoid receptor (NR3C1), corticotropin releasing hormone (CRH), corticotropin-releasing hormone receptor 1 and 2 (CRHR1/2), serotonin transporter (slc6a4), vasopressin and brain-derived neurotrophic factor.

DNA and RNA will be extracted from mucosal epithelial cells. The expression of candidate genes of the stress signaling pathways are investigated. The candidate genes are glucocorticoid receptor (NR3C1), corticotropin releasing hormone (CRH), corticotropin-releasing hormone receptor 1 and 2 (CRHR1/2), serotonin transporter (slc6a4), vasopressin and brain-derived neurotrophic factor. Furthermore a whole-genome methylation will be analysed.

DNA will be extracted from mucosal epithelial cells. The expression of candidate genes of the stress signaling pathways are investigated. The candidate genes are glucocorticoid receptor (NR3C1), corticotropin releasing hormone (CRH), corticotropin-releasing hormone receptor 1 and 2 (CRHR1/2), serotonin transporter (slc6a4), vasopressin and brain-derived neurotrophic factor.

Mother-child-interaction is investigated using Mannheim Rating Scales. Therefore a five-minute-videotape of the mother changing the infant's diapers and playing with the infant is used. Mannheim Rating Scales is a good validated standardized observation instrument. Stimulation and response from the mother as well from the infant are being recorded. Different communication channels can be used by mother and child (vocal, facial or motor). All behaviors are analysed at intervals of five seconds (event coding). Then the values are formed from the sum of the coded events. The scale ranges from 0 to 60. If there is no interaction, the scale is 0. If there is an interaction in each interval (every 5 seconds in a 5 minute videotape), the scale is 60. The mother-child interaction is better if the scale is higher.

The early infant development will be analyzed by general movements assessment by Prechtl. It is a validated diagnostic tool for the functional assessment of the young nervous system.

Maternal depression is assessed with the German long form of the Center for Epidemiological Studies Depression Scale (CES-D). It is a self-report questionnaire to measure depressive symptoms and it consists of 20 questions. For each question the response choice are assigned point values (how often a symptom occurred during the last week). The point values are summed to a total measure score. The score ranges from 0 to 60. Zero points represents no symptoms of depression, a score of 15 or higher is interpreted to indicate a risk of depression.

Social support is assessed with the short version of the German questionnaire for social support (Fragebogen zur sozialen Unterstützung, questionnaire on social support) scale (F-SozU K-22). The questionnaire records the subjectively perceived or anticipated support from the social environment. There are 22 items and the test person can indicate the degree of agreement on a five-level Likert scale (from 1 = does not apply to 5 = applies completely). The scale ranges from a minimum of 22 points to a maximum of 110 points. The higher the score, the better the subjectively perceived or anticipated support.

There will be a question to the household income per month and the parents' highest school-leaving certificate as well as the housing situation.

There will be a question about breastfeeding.

Symptoms for post-traumatic stress is assessed with the impact of event scale - revised (IES-R). It is a self-report questionnaire and consists of 22 questions. For each question the response choice are assigned point values (how often a symptom occurred during the last week). The sub-scale values are summed by the corresponding sub-scale items. The three sub-scales are: intrusion, avoidance and hyperarousal. The overall result is calculated by a formula. The score ranges from -4,36 to 2,99. A result above 0 is interpreted to indicate a risk of post-traumatic stress disorder.

Parental Bonding is assessed with the parental bonding questionnaire (PBQ). It consists of 25 items and each item is rated on a scale from 0 to 3 points (response range from "very like" to "very unlike"). There are four sub-scales and the point values of each sub-scale are summed to a total measure score. The four sub-scales are: impaired bonding, rejection and anger, anxiety about care, risk of abuse. The higher the score, the higher the risk of a disorder in each area of the sub-scale.

Parental stress is assessed with the German form of the parenting stress index (PSI). It consists of 48 items. The test person can indicate the degree of agreement on a five-level Likert scale (from 1 = does not apply to 5 = applies completely). There are 12 subscales, each consisting of 4 items and the points on the Likert scale are added. In each subscale there can be a minimum of 4 and a maximum of 20 points. The higher the score, the higher the parental stress.

Salivary cortisol is measured before and 20 minutes after heel lance, respectively after a stressful testing. The saliva is collected by a small cotton roll, which is placed in the infants' mouth. The cortisol is assayed in duplicate using an immunoassay, which is a validated test.