Consumption of oral contraceptive and family history as risk factors of Polydactyly

Abstract Background: Polydactyly is a common limb abnormality with little information about its risk factors. Objective: To determine the role of family history and maternal consumption of oral contraceptives as two risk factors of polydactyly. Methods: Through a random sampling method, a case-control study was implemented in Birjand hospital from 1997 to 1998, on 11 infants who had only polydactyly (Case group) and 44 singleton infants without any malformation (Control group). Mothers in the case and control group were interviewed and a questionnaire was completed. T-test, Chi-square and Fisher-test were used for data analysis. Findings: The average age of mothers in both groups did not show any significant difference (Case group: 27.3±3.2 and control group: 28.2±2.9). Polydactyly was most common in the left hand and less common in the right foot. Frequency of polydactyly was higher in baby-boys. In the history of the case group, family background of polydactyly and maternal consumption of oral contraceptives were observed. Conclusion: Family history of polydactyly and maternal consumption of oral contraceptives during the first month of pregnancy can be considered as risk factors of polydactyly.