Table 2 Infant outcome measures
Construct | Timing (WÂ =Â week/YÂ =Â Year) | Measure | Additional information | |||
|---|---|---|---|---|---|---|
| Â | W2 | W5 | W12 | Y1 | Â | Â |
Secondary outcomes | ||||||
 1. Behavior | ||||||
  1.1 Crying and fussing | x | x | x |  | 72-h study diary | Crying and fussing will be collected with a simply designed 72-h logbook that mothers fill in with lines [66]. |
  1.2 Sleep quality | x | x | x | x | 72-h study diary & Adjusted version Brief Infant Sleep Questionnaire (BISQ) | Mother will note the amount of sleep time in the crying and fussing diary at week two, week five, and week twelve [66]. Additionally, the mothers will complete the infant sleep-screening tool in reference to their child’s sleep during the past week at week two, week five, week twelve and year one [67]. |
 2. Physical health | ||||||
  2.1 Growth & health |  | x | x | x | Well-baby clinic logbook & Health interview and questionnaires | Growth and weight information will be copied from the well-baby clinic logbook at week 12 and year one. In addition, a health interview will be performed during the second home visit [61]. Also, the mother will fill in health questionnaires, based on the infant health interview, at week 12 and at 1 year of age [61]. |
  2.2 Physiological stress |  | x |  |  | Saliva cortisol | Infant cortisol reactivity and recovery will be measured with the saliva samples of the infant during the bathing session [64]. |
 3. General development | ||||||
  3.1 Regulation capacities |  |  | x | x | Infant Behaviour Questionnaire Revised (IBQ) – Short form | The IBQ is a 91-item questionnaire to assess infant regulation capacities with the Orienting/Regulation subscale [68]. |
  3.2 Language, cognitive and motor capacities |  |  |  | x | Ages and Stages Questionnaire- Third edition (ASQ-3) | The ASQ-3 is a 30-item validated questionnaire to assess communication, gross motor, fine motor, and adaptive problem solving skills [69]. The Personal-Social subscale of the ASQ will be used as a measure for social-emotional capacities (see 3.3). |
  3.3 Social-Emotional capacities |  |  |  | x | Brief Infant Toddler Social Emotional Assessment (BITSEA) | The BITSEA is a 42-item validated questionnaire to examine social and emotional behavior such as externalizing and internalizing behavior [70]. The Personal-Social subscale of the ASQ will be used (see 3.2) [69]. |
Secondary outcomes-Underlying mechanism | ||||||
 Intestinal microbiota | x | x |  | x | Stool samples | Stool will be collected from the diaper by the parents. Stool will be collected in tubes. |