Here is the design of a clinical trial:

Official Title: A Multicenter Clinical Trial To Assess The Efficacy Of Antenatal Maternal Supplementation With GOS/Inulin Prebiotics On Atopic Dermatitis Prevalence In High-Risk One-Year-Old Children.

Included conditions:
- Dermatitis, Atopic

Study Armgroups:
- {'label': 'PREBIOTICS', 'type': 'EXPERIMENTAL', 'description': '188 pregnant women', 'interventionNames': ['Dietary Supplement: PREBIOTICS']}
- {'label': 'PLACEBO', 'type': 'PLACEBO_COMPARATOR', 'description': '188 pregnant women', 'interventionNames': ['Other: PLACEBO']}

Interventions:
- {'type': 'DIETARY_SUPPLEMENT', 'name': 'PREBIOTICS', 'description': 'women will daily take a mixture of Galacto-Oligo-Saccharide/inulin (ratio 9:1) from inclusion to delivery', 'armGroupLabels': ['PREBIOTICS']}
- {'type': 'OTHER', 'name': 'PLACEBO', 'description': 'women will daily take placebo (maltodextrin) from inclusion to delivery', 'armGroupLabels': ['PLACEBO']}

Primary Outcomes:
- {'measure': 'atopic dermatitis prevalence at M12', 'description': 'prevalence will be evaluated according to UK party working group criteria', 'timeFrame': 'at 12 months of age'}

Please estimate the sample size based on the assumption: 
80% power, 5% alpha risk
Sample size
        According to the literature, the risk of AD at 1âyear in children at risk is estimated at 45%.24 We assume a 33% risk reduction for children whose mothers have been exposed to prebiotics, or a 30% risk of AD. With 80% power and 5% alpha risk, 326 participants are needed. To ensure statistical power, 376 participants (188 per group) will be randomised.