Table 1 Overview of study measurements and timepoints

Evaluation of intervention effects

Research questions 1, 2 and 3

Primary outcomes

Parental stress

 • Perceived stress

Questionnaire:

• Perceived stress Scale (PSS-10, [41])

x

x

x

•Postpartum Specific Anxiety Scale Research Short-Form (PSAS-RSF, 42)

x

x

x

 • Physiological stress

Hair cortisol [43, 44]

A tuft of hair of the parent will be assessed at T2. By dividing the hair tuft in segments, cortisol levels can be assessed retrospectively to compare pre- and post-intervention levels

Parental sensitive responsiveness

Questionnaire:

• Non-responsiveness scale (MRQ, [45])

x

x

x

• Mother-to-infant bonding scale (MIBS, [46])

x

x

x

• Questionnaire: Cry perception [47]

x

x

x

Growth and development of the infant

PCH assessments:

• Length

• Weight

• Van Wiechen scheme, [48]

Length, weight and Van Wiechen scores are assessed during each standard PCH contact moment. All data points from birth up to six months will be obtained from PCH files

Secondary outcomes

Parenting confidence

Questionnaire:

• Karitane Parenting Confidence scale (KPCS, [49]

x

x

x

Parental concerns with regard to crying feeding, sleeping of the infant

Questionnaire:

• Likert scales

x

x

x

Other measurements

Parent (and family) characteristics

Questionnaire:

• Date of birth

x

• Gender

x

• Country of birth of responding parent and his/her parents

x

• Educational level

x

• Relationship status

x

• Living situation (living with/without partner)

x

• Health

x

x

x

• Sleep

x

x

x

• Anxiety and depressive symptoms of the responding parent (Hospital Anxiety and Depression Scale (HADS[50, 51])

x

• Employment and working hours

x

Infant characteristics

Questionnaire:

• Parity

x

• Single or multiple birth

x

• Gestational age

x

• Gender

x

• Birth weight

x

• Health

x

x

x

Other

Questionnaire:

• Infant carrying

x

x

x

• Experience with infant massage

x

x

x

• (Breast)feeding

x

• Use of childcare

x

• The occurrence of stressful life events during the study period

x

• Received support from- and satisfaction with PCH

x

Evaluation of the intervention process

Research question 4

Evaluation of the intervention by participating parents

Evaluation questionnaire (participating parents)

x

Process of the intervention

Logbooks of the intervention sessions (PCH nurses)

Semi-structured logbooks will be completed after each intervention session

Intervention experiences of professionals (PCH nurses) and participating parents

Individual interviews with a number of PCH nurses and participating parents

A number of PCH nurses and parents who finished the intervention will be interviewed