Table 3

Characteristics of included case-control studies

Study/Year of Publication (country)




Risk of Bias/Notes

Correa 2003 [13]USA

Cases were 3278 Infants with congenital malformations related to diabetes. Controls were 3029 infants without congenital malformations. Maternal diabetes and intake of multivitamin were evaluated as a risk factors for congenital malformations

PCC included the use of multivitamin for 3 month before conception

The risk of congenital malformations related to diabetes was limited to infants of f diabetic mothers who had not taken multivitamin (OR 3.39 95% CI 1.79-8.63). Mother who had taken multivitamin had no increase risk of congenital malformations related to diabetes (OR 0.15 95% CI 0.00-1.99)

Medium (clear definition and selection of cases and controls, and outcomes, clearly defined outcome, not clear if the interviewers were blinded to the outcome, recall bias cannot be excluded during the interviews)

Key: OR= Odd Ratio, CI= Confidence Interval

Wahabi et al. BMC Pregnancy and Childbirth 2010 10:63   doi:10.1186/1471-2393-10-63

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