Here is the design of a clinical trial:

Official Title: A Randomized Controlled Trial of Cognitive Behavioural Therapy for Insomnia in Pregnancy

Included conditions:
- Insomnia
- Sleep Disturbance

Study Armgroups:
- {'label': 'Cognitive-Behavioural Therapy Group', 'type': 'EXPERIMENTAL', 'description': 'Participants receive 5 in-person weekly 1.5-hour sessions of cognitive-behavioural therapy for insomnia (CBT-I) for pregnant women, supervised by a registered, licensed clinical psychologist.', 'interventionNames': ['Behavioral: Cognitive Behavioural Therapy for Insomnia']}
- {'label': 'Treatment as Usual Group', 'type': 'ACTIVE_COMPARATOR', 'description': 'Participants receive usual obstetric care and are placed on a wait-list until six months postpartum. All activities or efforts participants make to treat or improve their sleep on their own is recorded and coded. After the final assessment six months postpartum, participants have the option of receiving 1.5-hour sessions (for a total of 5 session) of cognitive-behavioural therapy for insomnia (CBT-I) for pregnant women, supervised by a registered, licensed clinical psychologist.', 'interventionNames': ['Other: Active Control']}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Cognitive Behavioural Therapy for Insomnia', 'description': 'Cognitive behavioural therapy for insomnia (CBT-I) is an evidence-based psychotherapeutic intervention that combines cognitive and behavioural principles. Specifically, this therapy provides psychoeducation about thoughts contributing to the maintenance of sleep problems, and instruction in behavioural techniques to help decrease sleep onset latency and promote effective sleep maintenance.', 'armGroupLabels': ['Cognitive-Behavioural Therapy Group']}
- {'type': 'OTHER', 'name': 'Active Control', 'description': 'Participants will receive regular obstetric care and will be placed on a wait-list for CBT-I treatment after their final assessment. All activities women try for improving their own sleep problems between assessments will be recorded and coded for.', 'armGroupLabels': ['Treatment as Usual Group']}

Primary Outcomes:
- {'measure': 'Insomnia Severity Index', 'description': 'The ISI is a 7-item questionnaire designed to identify cases of insomnia and evaluate treatment outcomes. The ISI assesses severity of sleep onset, sleep maintenance and early wakening problems, sleep dissatisfaction, and perceived distress caused by sleep problems. It was found to be a clinically useful tool in assessing changes in insomnia symptoms in insomnia treatment research.', 'timeFrame': 'Change between 3 time-points: baseline, 7-week follow-up, 6-months postpartum follow-up.'}
- {'measure': 'Pittsburgh Sleep Quality Index', 'description': "The PSQI instrument is used in assessing one's sleep quality during the previous month. It consists of 19 self-rated items and 5 questions rated by the roommate or bed partner. There are seven components of the PSQI and these are subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medications, and daytime dysfunction.", 'timeFrame': 'Change between 3 time-points: baseline, 7-week follow-up, 6-months postpartum follow-up.'}
- {'measure': 'Actigraphy (Actiwatch II, Phillips, USA) - Circadian rhythm amplitude, acrophase, mesor', 'description': 'Actigraphy monitoring provides objective sleep data. The values for circadian rhythm amplitude, acrophase, and mesor will be combined for each participant to describe their full Circadian rhythm.', 'timeFrame': 'Change between 3 time-points: baseline, 7-week follow-up, 6-months postpartum follow-up'}
- {'measure': 'Actigraphy (Actiwatch II, Phillips, USA) - Sleep efficiency', 'description': 'Actigraphy monitoring provides objective sleep data. A sleep efficiency value is recorded by the actigrapher and will be reported.', 'timeFrame': 'Change between 3 time-points: baseline, 7-week follow-up, 6-months postpartum follow-up'}
- {'measure': 'Actigraphy (Actiwatch II, Phillips, USA) - Sleep latency', 'description': 'Actigraphy monitoring provides objective sleep data. A sleep latency value is recorded by the actigrapher and will be reported.', 'timeFrame': 'Change between 3 time-points: baseline, 7-week follow-up, 6-months postpartum follow-up'}
- {'measure': 'Actigraphy (Actiwatch II, Phillips, USA) - Total sleep time', 'description': 'Actigraphy monitoring provides objective sleep data. A total sleep time value is recorded by the actigrapher and will be reported.', 'timeFrame': 'Change between 3 time-points: baseline, 7-week follow-up, 6-months postpartum follow-up'}
- {'measure': 'Actigraphy (Actiwatch II, Phillips, USA) - Number and frequency of awakenings', 'description': 'Actigraphy monitoring provides objective sleep data. The number of times participants wake up during nighttime sleep is recorded by the actigrapher and will be reported.', 'timeFrame': 'Change between 3 time-points: baseline, 7-week follow-up, 6-months postpartum follow-up'}
- {'measure': 'Sleep Logs - Latency', 'description': 'Sleep logs provide self-reported subjective sleep. One of the variables participants will report is the amount of time they think it takes them to fall asleep.', 'timeFrame': 'Change between 3 time-points: baseline, 7-week follow-up, 6-months postpartum follow-up'}
- {'measure': 'Sleep Logs - Total sleep time', 'description': 'Sleep logs provide self-reported subjective sleep. Participants will be asked to report on their estimated total sleep time.', 'timeFrame': 'Change between 3 time-points: baseline, 7-week follow-up, 6-months postpartum follow-up'}
- {'measure': 'Sleep Logs - Number and frequency of awakenings', 'description': 'Sleep logs provide self-reported subjective sleep. Participants will be asked to report on the number of times they woke up during nighttime sleep.', 'timeFrame': 'Change between 3 time-points: baseline, 7-week follow-up, 6-months postpartum follow-up'}

Please estimate the sample size based on the assumption: 
The study aimed for over 90% power to detect a clinically significant change, accounted for a 20% attrition rate, and adjusted for pandemic-related dropouts.
Sample size {14}
        We used pre-post data available from our Phase IIb pilot trial, comparing in-person CBT-I to waitlist control (Î·2 = .41, f = 0.84), to conduct a power analysis. The effect size was large, and the power analysis indicated that we would need 18 participants to provide power over 90% to detect a clinically significant change of 8 points on the ISI [83]. Although longitudinal analyses of CBT-I show that gains are maintained up to two years posttreatment, we wanted to account for the possibility that the effects of treatment may decrease by 6 months postpartum. We therefore powered the RCT to detect a medium effect size (ï»¿f = 0.25), resulting in a total sample size of 44 participants (22 per group) over three assessment time points. Although retention in our studies has been excellent, we accounted for a potential attrition rate of 20% based on previous research in this area with longer follow-up periods [89], resulting in an initial total of 54 participants. When the protocol was amended due to the COVID-19 pandemic, 2 participants had to drop out of the intervention due to pandemic related schedule adjustments and we were unable to send actiwatches to 3 participants due to the temporary university closure. Therefore, the recruitment of 5 additional participants was needed to make up for the incomplete data and/or participation. To ensure there was a 1:1 ratio of participants per group, a final total of 62 participants will be recruited.