Here is the design of a clinical trial:

Official Title: Grandi Byen: Supporting Child Growth and Development Through Integrated, Responsive Parenting, Nutrition and Hygiene

Included conditions:
- Malnutrition, Child
- Development, Child
- Parenting

Study Armgroups:
- {'label': 'Standard well-baby care', 'type': 'NO_INTERVENTION', 'description': "Children in this arm (control group), as well as children in the two intervention groups, will receive standard care as outlined in the Essential Package of Health Services by Haiti's Ministry of Public Health and Population (MSPP). This includes a World Health Organization (WHO) immunization schedule of vaccines, high dose vitamin A supplements, and growth monitoring and promotion."}
- {'label': 'Nutrition Intervention', 'type': 'EXPERIMENTAL', 'description': 'Children in this arm will receive one egg per day for six months.', 'interventionNames': ['Dietary Supplement: Nutrition Intervention']}
- {'label': 'Grandi Byen', 'type': 'EXPERIMENTAL', 'description': 'This arm comprises a multicomponent intervention on responsive parenting, nutrition, hygiene, and one egg per day for six months for children.', 'interventionNames': ['Behavioral: Grandi Byen']}

Interventions:
- {'type': 'DIETARY_SUPPLEMENT', 'name': 'Nutrition Intervention', 'description': 'One egg per day for six months', 'armGroupLabels': ['Nutrition Intervention']}
- {'type': 'BEHAVIORAL', 'name': 'Grandi Byen', 'description': 'Multicomponent intervention on responsive parenting, nutrition, hygiene + one egg per day for 6 months', 'armGroupLabels': ['Grandi Byen']}

Primary Outcomes:
- {'measure': 'Child Growth: Changes in length-for-age Z-score (LAZ)', 'description': 'Child length or height will be measured in centimeters (cm). Length-for-age Z-scores will be calculated using the World Health Organization (WHO) growth standards, accounting for the child sex and age in months.', 'timeFrame': 'Baseline and months 3, 6, 9, and 12'}
- {'measure': 'Child Growth: Changes in weight-for-age Z-score (WAZ)', 'description': 'Child weight will be measured in kilograms (kg). Weight-for-age Z-scores will be calculated using the World Health Organization (WHO) growth standards, accounting for the child sex and age in months.', 'timeFrame': 'Baseline and months 3, 6, 9, and 12'}
- {'measure': 'Child Growth: Changes in head circumference-for-age Z-score (HCZ)', 'description': 'Child head circumference will be measured in centimeters (cm). Head circumference-for-age Z-scores will be calculated using the World Health Organization (WHO) growth standards, accounting for the child sex and age in months.', 'timeFrame': 'Baseline and months 3, 6, 9, and 12'}
- {'measure': 'Child Development: Changes in ASQ- Socio-Emotional (ASQ-SE) score', 'description': 'The Ages \\& Stages Questionnaire: Socio-Emotional Questionnaire (ASQ-SE2) will be used to assess and score child socio-emotional development.', 'timeFrame': 'Baseline and months 6 and 12'}
- {'measure': 'Child Development: Changes in ASQ Communication score', 'description': "The Ages \\& Stages Questionnaire (ASQ-3) will be used to assess and score children's communication skills.", 'timeFrame': 'Baseline and months 6 and 12'}
- {'measure': 'Child Development: Changes in ASQ Gross Motor score', 'description': "The Ages \\& Stages Questionnaire (ASQ-3) will be used to assess and score children's gross motor development.", 'timeFrame': 'Baseline and months 6 and 12'}
- {'measure': 'Child Development: Changes in ASQ Fine Motor score', 'description': "The Ages \\& Stages Questionnaire (ASQ-3) will be used to assess and score children's fine motor development.", 'timeFrame': 'Baseline and months 6 and 12'}
- {'measure': 'Child Development: Changes in ASQ Problem Solving score', 'description': "The Ages \\& Stages Questionnaire (ASQ-3) will be used to assess and score children's problem solving skills.", 'timeFrame': 'Baseline and months 6 and 12'}

Please estimate the sample size based on the assumption: 
The study assumes an intraclass correlation coefficient (ICC) of 0.7, which is typical for individual’s serial correlation in longitudinal studies. The statistical power is set at 0.80.
Sample size
        The study sample will comprise 600 mother-infant dyads, with 200 eligible pairs each assigned to one of the three study conditions. Using the software Optimal Design (Version 3.01) [64], we determined that a sample of 600 participants will lend our study adequate statistical power which allows us to observe an effect from the study interventions. Using the repeated measures module of the software under the setting of a cluster randomized trial with person-level outcomes and assuming an intraclass correlation coefficient (ICC) of 0.7, we found that the study will have a statistical power of 0.80 to detect an effect size of 0.338, which is slightly above the small effect size defined by Cohenâs d. The ICC of 0.7 is typical for individualâs serial correlation found from most longitudinal studies. If the ICC is reduced to 0.3, the study can detect an even smaller effect size of 0.31.