Parental exposures and risk of nonsyndromic orofacial clefts in offspring: a case-control study in Greece

Abstract

Objective: To investigate the association between cleft lip and/or palate and nongenetic factors in Greece.

Methods: We designed a case-control study including 35 patients with nonsyndromic cleft lip and/or palate, retrospectively selected, and 35 control patients matched for prefecture of residence, prospectively selected from pediatric population hospitalized for abdominal pain or injury. Parents were interviewed about drug uptake, diseases, habits, non-occupational exposure to pollutants, and occupation. Questions covered the period from one year before until three months after conception.

Results: High-risk paternal occupations (mostly farmers) were significantly more frequent in cleft lip and/or palate than in controls (p=0.039) and increased significantly the cleft lip and/or palate risk in offspring (OR: 3.00; 95% CI: 1.03-8.70). Maternal occupation did not correlate with cleft lip and/or palate. Parental disease, drugs uptake, hazardous habits, maternal folate supplementation and non-occupational exposure to pollutants did not correlate with cleft lip and/or palate. There was a suggestion of increased risk with maternal passive exposure to tobacco (OR: 1.81; 95% CI: 0.69-4.74) and with residential proximity to industries (OR: 1.70; 95% CI: 0.61-4.74).

Conclusions: Paternal high-risk occupations probably exert a teratogenic effect on spermatogenesis or result in maternal contamination, and deserve specific preventive policies. The relation of smoking and residential proximity to industries with occurrence of cleft lip and/or palate deserves further study.