Environmental Factors and Risk of Congenital Heart Anomalies : A Case-Control Study in Korea

Yun, Yong Soo; Shin, Ho Cheol; Syn, Hee Chul; Yoo, Keun Young; Park, Byung Joo; Ahn, Yoon Ok

Abstract

BACKGROUND
The multifactorial hypothesis is proposed as a working hypothesis which encompass both the genetic and environmental factors known to participate in the etiology of congenital heart anomalies. So, at the moment, it is believed that avoidance of suspected environmental factors in early pregenancy is most certain preventive measure of congenital heart anomalies. This study has been undertaken in order to find the possible environmental risk factors for congenital heart anomalies in Korea. METHOD: A total of 320 mothers of infants with congenital heart anomalies diagnosed at Seoul National University Hospital were included in this study as case group. And 413 mothers of healthy infants, who visited well baby clinic at the hospital during the same period of 2 years from 1987, comprised the control group. Data related to environmental risk factors including drug use during the first trimester of pregnancy, any other confounders were collected by direct interview using questionmaires. RESULT: There were positive associations for lower educational level of mother, indoor smoking habit of father, number of pregnancy, and of experience of previous abortion of mother, and multiple(or twin) birth. Relative risk estimates for the first trimester exposure to anti-emetics and herb medicine were 2.1(p<0.006) and 1.4(p<0.044), respectively. Data showed a positive association between anti-inflammatory drug exposure and congenital anomalies of pulmonary valve(OR=22.7, p<0.01), and between anti-histamine exposure and coarctation of aorata(OR=12.7, p<0.017). CONCLUSION: Environmental factors such as smoking habit of father, certain drugs used in early pregnancy, plays a role in the etiology of congenital heart anomlaies. Further studies, designed to focus on specific drug and to differentiate the effect of the suspected drug and to differentiate the effect of the suspected drug form that of the underlying conditions prompting its use, should be called upon.