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Table 4 Sample size estimations evaluating the effect of weight management interventions

From: Study protocol: differential effects of diet and physical activity based interventions in pregnancy on maternal and fetal outcomes—individual patient data (IPD) meta-analysis and health economic evaluation

Subgroups Control group SD Sample size required to detect a 2.5-kg reduction in gestational weight gain Control group: probability of adverse maternal and fetal outcomes Sample size required to detect a 30% reduction in adverse maternal and fetal outcomes
BMI Obese 7.5 300 0.30 770
  Overweight 7.5 300 0.20 1,290
  Normal 5.1 140 0.12 2,330
Age <20 years 7.12 270  
  ≥20 years 5.87 184
Ethnicity Caucasian 3.4 64
  Asian 3.8 78
  African 5.1 140
Parity <1 6.28 212
  ≥1 6.68 238
Risk factors like diabetes High risk 6.81 248
  Low risk 6.67 236