Table 1 Study inclusion and exclusion parameters
From: Perspectives on the design and methodology of periconceptional nutrient supplementation trials
Study inclusion parameters | Study exclusion parameters |
|---|---|
- Human studies from 1950 to July 2015, with no language restriction | - Studies with nutrient interventions commencing during, but not before pregnancy |
- Blinded and unblinded randomised trials | - If time of intervention was unclear |
- Community-/population-based studies | - Poorly defined control or comparison groups |
- Ongoing randomised trials studies with published methodologies, but awaiting trial closure | - Observational human studies |
- Clear definition of nutrient intervention | Â |
- Indication of period of periconceptional supplementation | Â |
- Definition of outcome variables (maternal, fetal, or infant outcomes). | Â |
- Studies in non-pregnant women prior to ascertainment of pregnancy | Â |
- Starting early in first trimester up to 28Â days after last menstrual period | Â |
- Individually randomised or population-based studies | Â |