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 al 56 199836 (1.29 to 1.45)<150 vs ≥150
Greenwood et al 57 201414 (1.10 to 1.19)Per 100
Li et al 58 201532 (1.24 to 1.40)<150 vs ≥150
Chen et al 59 20167 (1.03 to 1.12)Per 100
Stillbirth
Greenwood et al 57 201419 (1.05 to 1.35)Per 100
Chen et al 59 20169 (1.02 to 1.16)Per 100
Low birth weight/Small for gestational age
Ferandes et al 56 199851 (1.39 to 1.63)<150 vs ≥150
Santos et al 80 199829 (1.18 to 1.41)/24 (1.05 to 1.43)None/low vs high
Chen et al 81 201413 (1.06 to 1.21)Per 100
Greenwood et al 57 20147 (1.01 to 1.12)/10 (1.06 to 1.14)Per 100
Rhee et al 82 201538 (1.10 to 1.73)Lowest vs highest
Preterm birth
Santos et al 80 1998IndeterminateNone/low vs high
Maslova et al 84 2010No "important" associationLowest vs highest
Greenwood et al 57 20142 (−1.02 to 1.06)Per 100
Childhood acute leukaemia
Milne et al 89 201167 (1.20 to 2.32)None vs 3+ cups coffee
Cheng et al 92 201472 (1.32 to 2.16)None/low vs highest
Thomopoulos et al 93 201557 (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.