Outcomes Number of studies Certainty assessment Certainty assessment Certainty assessment Certainty assessment Certainty assessment Effect estimates Certainty
Risk of bias
Inconsistency
Indirectness
Imprecision
Publication bias
OR (95%CI)
Any congenital malformations 44 estimates from 9 studies Not serious Serious a Not serious Serious b Not serious 1.10(0.94,1.29) Low
Heart defects 15 estimates from 5 studies Not serious Serious a Not serious Not serious Undetected 1.06(1.02,1.11) Moderate
Cleft palate 7 estimates from 3 studies Not serious Serious a Not serious Serious b Undetected 0.78(0.37,1.64) Very Low
Other organ malformations 13 estimates from 3 studies Not serious Serious a Not serious Not serious Undetected 1.09(1.03,1.16) Moderate
Stillbirth or Miscarriage 17 estimates from 6 studies Not serious Serious a Not serious Serious b Not serious 0.60(0.40,0.91) Low
Preterm birth 4 estimates from 3 studies Not serious Serious a Not serious Serious b Undetected 1.05(0.72,1.55) Low
Other pregnancy outcomes 9 estimates from 3 studies Not serious Serious a Not serious Serious b Undetected 1.08(0.92,1.27) Low
a I2≥50%, and some of the confidence intervals did not overlap. b The confidence interval included a small reduction (5% reduction) and a substantial increase (54% increase). a I2≥50%, and some of the confidence intervals did not overlap. b The confidence interval included a small reduction (5% reduction) and a substantial increase (54% increase). a I2≥50%, and some of the confidence intervals did not overlap. b The confidence interval included a small reduction (5% reduction) and a substantial increase (54% increase). a I2≥50%, and some of the confidence intervals did not overlap. b The confidence interval included a small reduction (5% reduction) and a substantial increase (54% increase). a I2≥50%, and some of the confidence intervals did not overlap. b The confidence interval included a small reduction (5% reduction) and a substantial increase (54% increase). a I2≥50%, and some of the confidence intervals did not overlap. b The confidence interval included a small reduction (5% reduction) and a substantial increase (54% increase). a I2≥50%, and some of the confidence intervals did not overlap. b The confidence interval included a small reduction (5% reduction) and a substantial increase (54% increase). a I2≥50%, and some of the confidence intervals did not overlap. b The confidence interval included a small reduction (5% reduction) and a substantial increase (54% increase). a I2≥50%, and some of the confidence intervals did not overlap. b The confidence interval included a small reduction (5% reduction) and a substantial increase (54% increase).