Table 1

Summary of caffeine-related odds ratios expressed as percentage increased risk of harm (95% CI) for diverse negative pregnancy outcomes reported in meta-analyses published since 1998

AuthorsYearRisk, % (95% CI)Consumption, mg/day*
Miscarriage
Ferandes et al56199836 (1.29 to 1.45)<150 vs ≥150
Greenwood et al57201414 (1.10 to 1.19)Per 100
Li et al58201532 (1.24 to 1.40)<150 vs ≥150
Chen et al5920167 (1.03 to 1.12)Per 100
Stillbirth
Greenwood et al57201419 (1.05 to 1.35)Per 100
Chen et al5920169 (1.02 to 1.16)Per 100
Low birth weight/Small for gestational age
Ferandes et al56199851 (1.39 to 1.63)<150 vs ≥150
Santos et al80199829 (1.18 to 1.41)/24 (1.05 to 1.43)None/low vs high
Chen et al81201413 (1.06 to 1.21)Per 100
Greenwood et al5720147 (1.01 to 1.12)/10 (1.06 to 1.14)Per 100
Rhee et al82201538 (1.10 to 1.73)Lowest vs highest
Preterm birth
Santos et al801998IndeterminateNone/low vs high
Maslova et al842010No 'important' associationLowest vs highest
Greenwood et al5720142 (−1.02 to 1.06)Per 100
Childhood acute leukaemia
Milne et al89201167 (1.20 to 2.32)None vs 3+ cups coffee
Cheng et al92201472 (1.32 to 2.16)None/low vs highest
Thomopoulos et al93201557 (1.16 to 2.11)Lowest vs highest
  • *Level of maternal caffeine consumption (mg/day when given) used as the basis for estimating risk of harm.

  • CI, confidence interval.