Here is the design of a clinical trial:

Official Title: Sleep Apnea and Fetal Growth Restriction

Included conditions:
- Obstructive Sleep Apnea
- Fetal Growth Restriction
- Pregnancy Related

Study Armgroups:
- {'label': 'aPAP', 'type': 'EXPERIMENTAL', 'description': 'Nightly use of aPAP when sleeping through the date of delivery', 'interventionNames': ['Device: S9 VPAP Adapt']}
- {'label': 'No aPAP', 'type': 'NO_INTERVENTION', 'description': 'No use of aPAP (standard of care)'}

Interventions:
- {'type': 'DEVICE', 'name': 'S9 VPAP Adapt', 'description': 'Auto-titrated positive airway pressure', 'armGroupLabels': ['aPAP']}

Primary Outcomes:
- {'measure': 'Birth Weight', 'description': 'Weight of child at time of birth', 'timeFrame': '1 day'}

Please estimate the sample size based on the assumption: 
The assumptions include a baseline birth weight of 2535±234 g, a significance level (alpha) of 0.05, 90% power, a 5% loss to follow-up, and the use of a two-tailed t-test.
Sample size calculation
        The baseline birth weight of infants with FGR in the population from our primary study centre (Barnes-Jewish Hospital, St Louis, Missouri) is 2535Â±234âg (unpublished data). Based on these data, we calculated that 104 evaluable participants with OSA will need to be randomised to either PAP or control (stage 3) in order to have 90% power to detect a 150 g difference in birth weight in the PAP group compared with control. This is based on an alpha of 0.05, anticipated 5% loss to follow-up and a two-tailed t-test.
        The risk of OSA in high-risk obstetric populations (such as FGR) is as high as 35%.49 As we are screening participants for OSA risk by a brief telephone or in-person questionnaire (stage 1) prior to HSAT testing (stage 2), we estimate that there will be an OSA-positive HSAT in 30%â50% of these screened participants. Consequently, we estimate that we will need to assess HSAT in 200â350 participants in stage 2 in order to achieve our sample size of 104 evaluable participants for stage 3. We estimate needing to screen some 500â1000 participants in stage 1 in order to identify these 200â350 participants for stage 2. Based on an estimated combined total of 20â000 births annually with an estimated incidence of 15% of FGR at the above centres, we estimate 3000 pregnancies complicated by FGR each year. Accounting for participants who will not meet study inclusion criteria, or will decline to participate, the recruitment process is expected to last approximately 2 years.