Here is the design of a clinical trial:

Official Title: Healthy for my Baby- A Randomized Controlled Trial Assessing a Preconception Clinically Integrated Technological Intervention to Improve the Lifestyle of Overweight Women and Their Partners

Included conditions:
- Overweight and Obesity
- Pregnancy Complications
- Health Behavior
- Life Style
- Preconception Care

Study Armgroups:
- {'label': 'Intervention', 'type': 'EXPERIMENTAL', 'description': 'Healthy for my Baby Intervention', 'interventionNames': ['Behavioral: Healthy for my Baby']}
- {'label': 'Control', 'type': 'OTHER', 'description': 'Usual care', 'interventionNames': ['Other: Usual Care']}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Healthy for my Baby', 'description': 'Participants will start the preconception intervention by meeting with a health professional for a motivational interview session on healthy lifestyle habits. Following this interview, participants will have access to a mobile phone application that will allow them to track daily lifestyle modification goals. After a month, they will meet the health professional for a second motivational interview and review their progression. Participants will continue to make lifestyle changes through the preconception period by accomplishing smart goals followed daily in the mobile phone application.\n\nIf the woman becomes pregnant, the couple will participate in two more in-person motivational interviews, a month apart. The mobile application will be put in pregnancy mode, and participants will adapt their daily lifestyle goals for the pregnancy. Participants will continue to make lifestyle changes throughout pregnancy by accomplishing smart goals followed daily in the mobile phone application.', 'armGroupLabels': ['Intervention']}
- {'type': 'OTHER', 'name': 'Usual Care', 'description': 'Participants in the control group will receive standard advice on healthy lifestyle habits as provided by their usual care provider. They will receive standard medical care in preconception and pregnancy.\n\nTo improve compliance with the study follow-up, participants in this group will have access to a simplified version of the mobile application that contains a fertility calendar and a research visit calendar. This version of the application does not include lifestyle goals or any information on healthy lifestyle habits.', 'armGroupLabels': ['Control']}

Primary Outcomes:
- {'measure': "Women's diet quality in preconception measured with the Canadian-Healthy Eating Index- 2007", 'description': "Women's C-HEI score will be measured with two or three online 24 hour dietary recalls (R24W tool) at each time point. Value range 0-100 with a higher score indicating better diet quality. The change of the score in time during the preconception period will be compared between the groups.", 'timeFrame': '0, 2, 4, and 6 months'}

Please estimate the sample size based on the assumption: 
The assumptions include a significance level (alpha) of 5%, a power of 80%, and a 20% attrition rate.
Sample Size Calculation and Analysis Plan
        
          Sample Size Calculation
          Since no minimally clinically important effect size has been defined for the HEI score, our effect size has been estimated as a plausible effect of the intervention based on the preliminary results of the Obesity Fertility trial (71), which demonstrated a 12.5 Â± 13.0 points increase in the average HEI score of women with obesity and infertility after a 6-month lifestyle intervention (unpublished data). An increase of 12 points in the average HEI score was also observed in breast cancer survivors with obesity who received a 6-month dietetic intervention (75). To detect a 10% difference in the average HEI score between groups with a 13-point standard deviation, an alpha value of 5% and 80% power, we will need to recruit 27 women per group (76). To account for a 20% attrition rate (77), a total of 68 women and their partners will be recruited.
        
        
          Statistical Analysis Plan
          Study results will be analyzed at the end of the trial following intent-to-treat principles. Participants' baseline characteristics will be reported to assess group comparability at baseline in preconception and at the beginning of pregnancy. A statistical significance threshold of 5% will be used for all analyses. Statistical analyses will be performed using the Statistical Package for the Social Sciences (SPSS version 26) and R (Version 4.0.2) software. No interim analysis will be performed.
        
        
          Primary Outcome Analysis
          Our primary endpoint is the difference in the evolution of the HEI score between study groups in time, which will be assessed using a mixed linear model of the HEI score integrating the effects of time as a continuous variable, study group, and the interaction between the study group and time. This statistical model has been chosen because it will allow us to account for (1) the different lengths of preconception follow-up that will arise as a result of women becoming pregnant throughout the study; and (2) variable timing and number of the R24W questionnaires performed by the participants (due to non-adherence to the protocol) (78). The average HEI score in each group at 2, 4, and 6 months will also be compared using standard mixed-model repeated measures ANOVA with post-hoc Student's t-tests with Bonferroni correction for multiple comparisons. As a secondary analysis, Kaplan-Meier survival curves of women who have increased their HEI score by 10 points or more will be produced, with censoring for dropout or occurrence of pregnancy.
        
        
          Secondary Outcome Analysis
          For the main secondary outcome for the pregnancy phase of the trial, we will use a Chi-squared test to compare the proportion of women who have an adequate gestational weight gain in each group.
          For the targeted analysis of urine biomarkers, the concentration of around 40 metabolites will be compared between baseline, 2 months in preconception and 24â26 weeks of pregnancy using repeated measures ANOVA or Friedman test with a Bonferroni adjustment for multiple comparisons. The correlation between the metabolite derived diet quality score and the C-HEI score will be evaluated using Pearson's correlation.
          Although our sample size is fairly small, an exploratory multivariate analysis of non-targeted metabolome profiles will be realized using both unsupervised ânatural clusteringâ analysis and Supervised Random Forest classification.
          For the other secondary outcomes, continuous variables will be assessed using Student's t-tests or Mann-Whitney tests as appropriate. Dichotomic variables will be analyzed using Chi-squared tests or Fisher's exact test as appropriate.
          For participants who achieve a pregnancy prior to the 2-month food recall and/or 3-month preconception visit, lifestyle and anthropometric outcomes at the first pregnancy visit will be used to complete the preconception analysis. Women will be able to signal the occurrence of a pregnancy through the mobile application as soon as a period is missed. The application software will immediately notify the research team which will allow completion of data collection prior to the occurrence of significant pregnancy symptoms such as hyperemesis.