The Role of Environmental Factors in the Etiology of Nonsyndromic Orofacial Clefts

Background: Nonsyndromic orofacial clefts (NSOFCs) represent the most common congenital anomalies in the head and neck region. Multiple factors contribute to the occurrence of this anomaly. The etiology of NSOFCs in the Ethiopian population has not been investigated prior to this study.

Aims of the Study: To assess the role of maternal environmental factors in the occurrence of NSOFCs in the Ethiopian Population.

Methods: The authors used unmatched case control study design and evaluated the role of environmental factors to the occurrence of NSOFCs in the Ethiopian population. The participants were recruited from the same institution (Yekatit 12 Hospital Medical College). The authors studied 760 mothers (359 mothers of children born with NSOFCs and 401 mothers of children born without any congenital anomalies). Univariate and multivariate logistic regression analyses were used to calculate relative risk by odds ratio and 95% confidence interval.

Results: Mothers who gave history of bronchial asthma and mothers who were admitted for threatened abortion had a higher risk of delivering a child with NSOFCS P value=0.013; AOR=0.194, 95% CI [0.053-0.712], P value <0.001; AOR= 0.179, 95% CI [0.091-0.352] respectively. Higher number of children with NSOFCs were born to mothers who were exposed to diagnostic X-ray investigation during early pregnancy than those who were not exposed P value 0.048; AOR=0.375, 95% CI [0.142-0.990].

Conclusion: Maternal exposure to diagnostic x-ray, maternal chronic illness like bronchial asthma and threatened abortion were found to be associated with the occurrence of NSOFCS in the studied population.