**5. Conclusion**

66 Congenital Heart Disease – Selected Aspects

 **Air Pollution;** Ambient air pollution such carbon monoxide (CO), nitric oxide (NO), ozone (O3), and sulfur dioxide (SO2) may cause CHD dependent on pollutant levels (Ritz et al., 2002; Rankin et al., 2009). A study by Gilboa et al, observed positive associations between carbon monoxide and isolated ASD, TOF, particulate matter < 10 μm in diameter and isolated ASD as well as between ozone and VSD (Gilboa et al., 2005). From a study by Dadvand et al, exposure to CO and NO has been associated with ventricular septal defect and cardiac septa malformations. CO was also associated with congenital pulmonary valve stenosis and NO was associated TOF (Dadvand et al., 2011). Further studies are also required to clarify if air pollution exposure influences the

 **Maternal Home Tap Water Consumption;** It has a positive association between a mother's consumption of home tap water during the first trimester of pregnancy and cardiac anomalies. This was unrelated to water contamination, mother's race, or her

 **Waste Sites;** Many of the recent studies about possible increased risk of CHD in communities situated near hazardous waste sites are inconsistent (Croen et al., 1997)

 **Ionizing Radiation**; there are few reports on possible associations of CHD with maternal exposure to ionizing radiation in occupational settings or as part of medical or dental evaluations. Studies found no clear evidence of any association. Further studies are also required to clarify the precise relationship between these factors and CHD.

Excluding genetic counseling, the genetic disorder cannot be protected against; simple guidelines to pregnant mothers for prevention of CHD in their newborns are good diet, physical activity, lifestyle, environments and occupation that the parents should discuss with their primary care provider or obstetrician. Women of childbearing age also should obtain prenatal care, including testing for diabetes and past rubella immunization, they should also discuss any medication use with their obstetrician; and should avoid contact with ill people, especially those with rubella or influenza. Women of childbearing age should take 400 micrograms of folic acid on a daily basis starting before pregnancy, which can reduce congenital heart and neural tube defects, and should avoid certain types of behaviors such as exposure to organic solvents, smoking and heavy alcohol use. If a woman has no immunity to rubella, she should get vaccinated prior to pregnancy. Preconception care and appropriate dietary management for women with phenylketonuria should be an important strategy. Detection and appropriate management of diabetes before and during pregnancy should be an important step for reducing risk of CHD in offspring. Avoidance of medications that are suspected to cause congenital defects, including congenital heart disease, should be taken, and the medications should have warnings about that risk to allow mothers and physicians to make informed decisions about the risks and benefits of the use of the medication during pregnancy. Recommendations also are possible for screening for

with maternal reports of exposure to insecticides (Shaw et al., 1999).

risk for CHD.

**4. Prevention** 

educational level (Shaw et al., 1990).

and may not ultimately prove to be causal.

et al., 1989). In the Baltimore-Washington Infant Study (BWIS), potential exposure to herbicides and rodenticides was associated with an increased risk of TGA, while potential exposure to pesticides was associated with TAPVR and VSD. A case-control study of various end-product uses reported an increased risk of conotruncal defects

> The number of patients, both children and adults, with CHD has continued to rise. The most common reasons for CHD are associated with multiple factors. Epidemiology studies reveal underestimated cases of CHD, and together with the etiology the studies help to define potential risk factors for CHD. The epidemiology and etiology of CHD also help prioritize the areas needed for intervention and additional regulations the public health officers may impose. Patients and parents of babies with CHD must understand the significance of routine medical checkups, which can be accomplished though an effective transition program and collaboration among healthcare providers.
