A hidden epidemic of birth defectsJan 30, 2006 | Scripps Howard News Service
There's a largely hidden epidemic of birth defects running through the world's infants and children, striking about 8 million every year, about 6 percent of those born, according to a new study.
An estimated 3.3 million children under age 5 die from a serious birth defect of genetic or partially genetic origin, while another 3.2 million of those who survive are mentally or physically disabled for life, researchers from the March of Dimes reported Monday.
It is the first global effort to calculate the toll.
Estimates are based on data from the relatively few countries where birth defects have been well-documented and where projections based on the demographics, economies and cultures of those where conditions are less well-recognized. Those estimates show that the vast majority of the impact from birth defects is felt in middle- and low-income countries.
The report does not attempt to calculate the hundreds of thousands more infants born each year with birth defects caused by exposure during pregnancy to environmental toxins, alcohol, tobacco smoke and diseases such as rubella and syphilis.
The March of Dimes _ an advocate for ending birth defects in this country since 1938 went international in 1998 to help set up a global alliance of organizations dedicated to preventing and correcting birth defects. The new report is part of a concerted effort to place birth defects on the public-health agenda of national governments and international health organizations.
"This is a serious, vastly unappreciated and under-funded public-health problem," said Dr. Jennifer Howse, president of the March of Dimes.
Christopher Howson is an epidemiologist and vice president for Global Programs with the March of Dimes who worked on the report. He said the report's data on 193 countries is still too imprecise to do valid comparisons of birth-defect rates between countries, but does allow broad comparisons across regions and among countries of different income levels.
"We can't say from the data we have why the rate in the U.S. is 47.8 per 1,000 births and the rate in the Russian Federation is 42.9, but we do know that there are a lot of factors that are common across national boundaries," Howson said.
In addition to addressing poverty and the health problems that go with it, the report notes there are significant demographic reasons why poorer nations have higher birth-defect rates. They include: more women of advanced age having children and a greater frequency of marriages between individuals who are close blood relatives.
Five common defects of genetic or partially genetic origin accounted for about 26 percent of such birth defects in 2001: congenital heart defects (more than 1 million), neural tube defects (324,000), Down syndrome (218,000), hemoglobin disorders called thalassemia and sickle cell disease (308,000) and another blood-related defect called G6PD deficiency (177,000).
"There are a lot of misperceptions around the world about birth defects, including that they're a problem only rich nations can afford to address or that only countries with sophisticated health-care systems can make any progress," Howson said.
Many birth defects aren't recognized or considered a cause of death in nations where young children die so readily from infectious diseases, the report says. Even in the most developed nations, only about 50 percent of birth defects are accurately diagnosed.
Yet, "with some relatively low-tech interventions and training that we're advocating in the report, a lot of improvement could be attained," Howson said.
Among the proposed interventions: folic-acid supplementation to prevent neural tube defects, such as spina bifida; iodination of salt to prevent congenital hypothyroidism; and rubella vaccinations to prevent a congenital rubella syndrome.
"Experience from high-income countries shows that overall mortality and disability from birth defects could be reduced by up to 70 percent if the recommendations in this report were broadly implemented," said Dr. Arnold Christianson of the National Health Lab Service and University of the Witwatersrand in Johannesburg, South Africa.
Howson noted that many middle-income nations have birth-defect rates roughly equivalent to those found in the United States in 1960, which have been reduced by 62 percent over the past four decades.
Other interventions proposed by the report include educating health workers, political leaders and the general public in each country about the toll of birth defects and the risk factors that might be changed to avoid them, such as having children at older ages and intermarriage.
Moreover, Howson said, general education in medical genetics would not only help various countries curb birth defects, but could help poorer nations tap into the promising fields of genetic testing for disease risk and the tailoring of medicines according to genetic profiles.