The Bloom Study - a Safe and Healthy Start in Life

The aim of the Bloom Study is to promote healthy weight development among infants through a home-based health promoting intervention implemented in the Danish setting of community health nurses. The intervention begins during pregnancy and runs until the child reaches the age of 30 months.

The Bloom Intervention was developed over a six-year period from 2017 to 2023 according to the Intervention Mapping approach and based on a co-creation process.

The Bloom Intervention is evaluated in a cluster-randomized trial involving 22 Danish municipalities (11 intervention and 11 control). All children born from first-time mothers over a period of 12 months are invited to participate.

Study Overview

• Status: Recruiting
• Conditions: Overweight, Childhood; Obesity in Children
• Intervention / Treatment: Behavioral: Multi-behavioural

Detailed Description

Childhood overweight and obesity are major public health challenges. In Denmark, 14% of children have overweight or obesity at school entry, rising to 19% by school leaving, with higher prevalence levels among children from low socio-economic positions and ethnic minority backgrounds.

Early intervention is crucial since childhood obesity is hard to reverse, and infancy presents an opportunity to address modifiable risk factors. It is well-documented that both genetic, behavioral, psychosocial, and environmental factors play key roles. Modifiable risk factors include feeding practices, physical activity, screen use, and sleep. Additionally, growing evidence suggests that psychological stress in early life due to unmet socio-emotional needs may lead to disrupted energy balance homeostasis, resulting in weight gain.

The Bloom Study is designed to address food and meals, motor skills and movement, screen use, sleep, and sense of security in the family. The intervention targets first-time families, with a special focus on reaching all families across varying socio-economic positions and ethnic backgrounds. Also, the Bloom intervention has a strong focus on involving fathers/partners. It is delivered through the established and highly accepted system of community health nurses in Denmark.

The intervention is initiated during pregnancy and continues until the child reaches 30 months of age. The main intervention components include: 1) an extra home visit during pregnancy, 2) an extra home visit when the child ais 18 months, 3) an extra home visit when the child is 30 months, 3) telephone consultations, 4) parent groups, and 5) a video library for parents.

An important element of the implementation strategy is to ensure that the intervention design and implementation are compatible with the existing practices, priorities, and values within the system of Danish community health nurses. Additionally, the implementation of the Bloom Study will be supported by five main activity components: 1) training of community health nurses including a five-day training course, supervision, and a comprehensive implementation manual containing instructions for standardized delivery of the intervention, 2) selection of local program ambassadors among community health nurses in the municipalities, 3) regular contact with the research group including assignment of one main contact person, 4) meeting activities including start-up meetings, network meetings across municipalities, and local staff meetings, and 5) partial economic compensation.

The Bloom Study is evaluated within a cluster-randomized controlled trial (cluster-RCT) with 22 municipalities randomly allocated to intervention (11 municipalities) and control (11 municipalities). The intervention is initiated during pregnancy and continues until the child reaches 30 months of age. Follow-up data are collected at child age of 36 months. Primary outcome is Body Mass Index (BMI) z-score at child age of 36 months.

• Study Type: Interventional
• Enrollment (Estimated): 3500
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Camilla T Bonnesen; Phone Number: +4565507883; Email: catb@sdu.dk
• Study Contact Backup: Name: Mette Rasmussen; Phone Number: +4565507319; Email: mera@sdu.dk

Study Locations

• Denmark
  • Copenhagen, Denmark, 1455
    • Recruiting
    • National Institute of Public Health, University of Southern Denmark
    • Contact: Camilla T Bonnesen, Researcher; Phone Number: +4565507883; Email: catb@sdu.dk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

All children born from first-time mothers being in gestation week 20 between November 1st 2024 and October 31st 2025.

Exclusion Criteria:

Not being able to receive digital post.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intervention; The Bloom Intervention adds to standard municipal care (5-6 home visits) with a prenatal visit, visits at 18 and 30 months, up to eight phone consultations, parent groups, and a video library. Home visits: Three extra visits include one in pregnancy week 22-24 to build trust and assess needs using a dialogue tool focused on social and demographic factors. Visits at 18 and 30 months support sustained progress and address new challenges. Phone consultations: Up to eight calls support breastfeeding, bottle-feeding, and complementary feeding. Phone consultations at 12 and 24 months aid in maintaining healthy habits during key transitions, like starting daycare. Parent groups: Encourage shared experiences among parents, with policies promoting father participation. Video library: Includes 62 videos on nutrition, motor skills, sleep, etc., with 48 available in multiple languages for wider access.	Behavioral: Multi-behavioural; The Bloom Study is implemented in an existing and highly accepted health service delivered by community health nurses. Beyond focusing on food, meals, motor skills and movement, the intervention also target sleep and family sense of security. The intervention commence in pregnancy and continues until the child is 2½ years old.; Other Names: Sleep; Motor skills and movement; Screen use; Family sense of security; Food and meals
No Intervention: Control; The families in the control municipalities will receive standard deliveries from the community health nurses

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
BMI z-score	Between group difference in BMI z-score based on WHO references. Weight is measured by portable weights (Seca 887) and height is measured by measurement tapes according to a standardized instruction.	36 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weight status	Between group difference in prevalence of children with underweight, overweight and obesity based on WHO references. Weight is measured by portable weights (Seca 887) and height is measured by measurement tapes according to a standardized instruction.	36 months
BMI z-score	Between group difference in BMI z-score based on WHO references. From birth to 10 months weight is measured by portable weights approved for standard use by community health nurses and according to a standardized instruction (journal records). At age 18 and 30 months, weight is measured by portable weights (Seca 887). From birth to 18 months length is measured by a mobile measuring mat (Seca 201) according to a standardized instruction. At age 30 months, height is measured by measurement tapes according to a standardized instruction.	Few days after birth, Within first week after returning to home, Within first months, 2 months, 4-6 months, 8-10 months, 18 months, 30 months
Fat mass (kg)	Between group difference in fat mass measured by bioimpedance analysis. Bioimpedance will be measured by the Impedimed SFB7 device.	36 months
Fat free mass (kg)	Between group difference in fat free mass measured by bioimpedance analysis. Bioimpedance will be measured by the Impedimed SFB7 device.	36 months
Fat mass index in kg/m2	Between group difference in fat mass index measured by bioimpedance analysis. Bioimpedance will be measured by the Impedimed SFB7 device.	36 months
Fat free mass index (kg/m2)	Between group difference in fat free mass index measured by bioimpedance analysis. Bioimpedance will be measured by the Impedimed SFB7 device.	36 months
% Fat mass	Between group difference in % fat mass index measured by bioimpedance analysis. Bioimpedance will be measured by the Impedimed SFB7 device.	36 months
% Fat free mass	Between group difference in % fat free mass index measured by bioimpedance analysis. Bioimpedance will be measured by the Impedimed SFB7 device.	36 months

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Child social-emotional development	Measurement instrument: The Ages & Stages Questionnaires: Social-Emotional, Second Edition (ASQ:SE-2) (parents' questionnaires). The questionnaire includes a total of 27 (12 months), 31 (24 months) and 36 (36 months) questions each with possible scores of 0, 5, 10 or 15 from which a total sum score is generated. A higher score indicates a higher extent of socio-emotional concerns.	12, 24 and 36 months
Child mental health	Measurement instrument: Strengths and Difficulties Questionnaire (SDQ, 2-4 years) (parents' questionnaires) The instrument five subscales: Conduct problems (score range from 0-10); emotional symptoms (score range from 0-10); hyperactivity (score range from 0-10); peer problems (score range from 0-10); and prosocial behaviour (score range from 0-10). A total difficulties score can be generated by summing the scores of all scales except the prosocial behaviour scale (score range from 0-40). The extent of difficulties increases with increasing score.	24 and 36 months
Child eating behaviour	Measurement instrument: Child Eating Behaviour Questionnaire (BEBH) (parents' questionnaires) The questionnaire covers eight domains: Food responsiveness, Emotional over-eating, Enjoyment of food, Desire to drink, Satiety responsiveness, Slowness in eating, Emotional under-eating and Food fussiness. For each item the response categories (including scoring) is: Never=1, Rarely=2, Sometimes=3, Often=4, Always=5, from which a domain mean score is generated. Higher scores indicate more frequent demonstrations of behaviours characterizing the trait of the domain.	24 and 36 months
Parental feeding practices - < 2 years, solid food	Measurement instrument: The Feeding Practices and Structure Questionnaire (< 2 years, solid food) The measure comprises a total of 34 items, scored on a 5-point Likert scale with higher scores indicating greater endorsement of that practice. The questionnaire covers six domains of non-responsive feeding practices: Feeding on demand (4 items), Using food to calm (6 items), Persuasive Feeding (7 items), Parent-led feeding (4 items), Family meal environment (4 items), and Using (non-) food rewards (9 items).	12 months
Parental feeding practices, >= 2 years	Measurement instrument: The Feeding Practices and Structure Questionnaire (FPFQ-28) The measure comprises a total of 28 items, scored on a 5-point Likert scale with higher scores indicating greater endorsement of that practice. The questionnaire covers seven domains of non-responsive feeding practices: Reward for Behaviour (4 items), Reward for Eating (4 items), Persuasive Feeding (6 items), Overt Restriction (4 items), Covert Restriction (4 items), Structured Meal Setting (3 items), and Structured Meal Timing (3 items).	24 and 36 months
Parents' well-being	Measurement instrument: WHO5 (parents' questionnaires) The WHO-5 index is scored based on responses to five statements rated on a 6-point Likert scale. The raw sum score ranges from 0 to 25. Higher scores indicate better well-being.	6, 12, 24 and 36 months
Sensitive parenting	Measurement instrument: The Parental Reflective Functioning Questionnaire (PRFQ), subscale Certainty about Mental States (parents' questionnaires) The subscale includes 6 items with a seven-point response key. The higher the mean score, the higher the degree of sensitive parenting.	6, 12, 24 and 36 months
Parental feeding practices - < 2 years, milk	Measurement instrument: The Feeding Practices and Structure Questionnaire (< 2 years, milk) The complete measure comprises a total of 18 items, scored on a 5-point Likert scale with higher scores indicating greater endorsement of that practice. The complete questionnaire covers four domains of non-responsive feeding practices. The following two domains are included at 6 months: Using food to calm (5 items), and Parent-led feeding (6 items).	6 months
Parents' self-efficacy related to child sleep	Measurement instrument: Uppsala Parental Self-Efficacy about Infant Sleep Instrument (UPPSEISI)(parents' questionnaires) The UPPSEISI includes 11 items with total scores ranging from 11 to 55 points. Higher values on UPPSEISI indicate a higher level of parental self-efficacy. The 11 items cover two domains: The Child's Need for Sleep (CNS) domain (8 items), and the Arduous Parenting (AP) domain (3 items).	6, 12, 24 and 36 months
Parents' self-efficacy related to parenthood	Measurement instrument: Perceived Maternal Parenting Self-Efficacy (PMP S-E) tool (parents' questionnaires). The complete tool consists of 20 items. Higher scores indicate higher self-efficacy. The complete tool covers four domains. The following domain is included: Evoking behaviour (7 items).	6, 12, 24 and 36 months
Parental stress	Measurement instrument: The 16-item version of the Parental Stress Scale (parents' questionnaires) (Pontoppidan et al., 2018). The scale applies a five-point response key. Overall possible scores on the scale range from 16 - 80. The higher the score, the higher the measured level of parental stress.	6, 12, 24 and 36 months
Breastfeeding	Indicators: 1) Ever breastfeeding, 2) Duration of exclusive breastfeeding, 3) Duration of partial breastfeeding. Measurement tool: Developed for the study	6, 12 and 24 months
Bottle feeding with infant milk formula	Indicators: 1) Ever given infant milk formula, 2) Amount of daily infant milk formula at 6 months of age, 3) Duration of bottle feeding (infant milk formula) Measurement tool: Developed for the study	6 and 24 months
Introduction to complementary food	Indicator: Age (in months and weeks) at introduction to complementary food Measurement tool: Developed for the study	6 and 12 months
Use of baby food squeeze pouches	Indicators: 1) Ever use of baby food squeeze pouches, 2) Method for feeding the child from the food squeeze pouch Measurement tool: Developed for the study	6 and 12 months
Child screen use	Indicators: 1) Daily screen watching time, 2) Frequency of screen use for soothing Measurement tool: Developed for the study	6, 12, 24 and 36 months
Child sleep	Indictors: 1) Child night-time sleep duration and 2) Child night-time sleep quality Measurement tool: Developed for the study	6, 12, 24 and 36 months
Motor skills	Indicator: Frequency of tummy time Measurement tool: Developed for the study	6 months
Movement	Indicator: Frequency of active play with the child Measurement tool: Developed for the study	6 and 12 months
Child placed in fixed sedentary position	Indicator: Time (daily) child fixed in sedentary sitting position Measurement tool: Developed for the study	6 and 12 months

Collaborators and Investigators

• Sponsor: University of Southern Denmark
• Collaborators: University of Copenhagen; National Institute of Public Health, University of Southern Denmark; Danish Centre for Health Economics (DaCHE), University of Southern Denmark; Danish Research Centre for Migration, Ethnicity and Health, University of Copenhagen; Centre for Childhood Health; The Centre for Health Economics, University of York
• Investigators: Principal Investigator: Camilla T Bonnesen, National Institute of Public Health, University of Southern Denmark

Publications and helpful links

General Publications

• Bonnesen CT, Rasmussen M, Kierkegaard L, Carlsson RR, Jensen MP, Ubbesen TR, Madsen KR, Thygesen LC, Krolner RF, Brautsch LAS, Rosing JA, Kongstad LP, Vaever MS, Egmose I, Pedersen TP. Study protocol for a cluster-randomized controlled trial of a universal home-based, multi-component intervention to promote healthy weight development in children during infancy and toddlerhood in denmark: the bloom study. BMC Public Health. 2025 Aug 27;25(1):2952. doi: 10.1186/s12889-025-24352-1.

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2024
• Primary Completion (Estimated): March 31, 2029
• Study Completion (Estimated): March 31, 2029

Study Registration Dates

• First Submitted: November 14, 2024
• First Submitted That Met QC Criteria: November 21, 2024
• First Posted (Actual): November 26, 2024

Study Record Updates

• Last Update Posted (Actual): December 22, 2025
• Last Update Submitted That Met QC Criteria: December 15, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Obesity; Randomized controlled trial; Children; Overweight; Sleep; Intervention; Infants; Home-based; Weight status; The Bloom Study; Community health nurses; Multi-component; Health promotion and prevention; Food habits and meals; Motor skills and movement; Screen use
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Pathological Conditions, Signs and Symptoms; Behavior; Nutritional and Metabolic Diseases; Signs and Symptoms; Behavior, Animal; Overweight; Obesity; Pediatric Obesity; Feeding Behavior; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages; Nervous System Physiological Phenomena; Food; Movement; Sleep; Meals
• Other Study ID Numbers: H-24032126

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: A formal application with reasonable request must be approved by the study's management group. Data will only be shared as long as there is a legal basis for the disclosure.
• IPD Sharing Access Criteria: A formal application with reasonable request must be approved by the study's management group. Data will only be shared as long as there is a legal basis for the disclosure.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Study Data/Documents

1. Study Protocol
2. Statistical Analysis Plan

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No