Important Facts
Congenital anomalies (also known as birth defects) affect approximately 1 in 33 babies and cause approximately 3.2 million birth defect-related disabilities each year.
An estimated 270,000 newborns die each year from congenital anomalies during the first 28 days of life.
Congenital anomalies can cause long-term disabilities that have a significant impact on individuals, families, the health care system and society.
The most common serious congenital anomalies are heart defects, neural tube defects, and Down syndrome.
Congenital anomalies can be genetic, infectious or environmental in origin, but in most cases, it is difficult to determine the exact cause.
Many congenital anomalies can be prevented. For example, vaccination, adequate intake of folic acid and iodine, and adequate prenatal care are the keys to prevention.
In many countries, congenital anomalies and prematurity are important causes of death, chronic disease and disability in childhood. In 2010, the World Health Assembly adopted a resolution calling on all Member States to promote primary prevention and health for children with congenital anomalies through
Developing and strengthening registration and surveillance systems ;
Developing expertise and building capacity ;
Strengthening research and investigation in etiology, diagnosis and prevention;
Promote international cooperation.
Causes of 3.1 million neonatal deaths in 193 countries in 2010
Definition
Congenital anomalies are also known as birth defects, congenital diseases or congenital malformations. Congenital anomalies can be defined as the presence of structural or functional abnormalities at birth, including metabolic disorders.
Causes and risk factors
Although about half of congenital anomalies cannot be attributed to a specific cause, there are some known causes or risk factors.
Socioeconomic factors Although this may be an indirect determinant, congenital anomalies are more common in families and countries with limited resources. It is estimated that about 94% of severe birth defects occur in middle- and low-income countries, where mothers are more susceptible to macronutrient and micronutrient malnutrition and may be more exposed to any substance or factor that causes or increases abnormal prenatal development, especially infections and alcohol. Older maternal age also increases the risk of certain chromosomal abnormalities, including Down syndrome.
Genetic factors
Consanguineous marriages (consanguineous unions) increase the prevalence of rare genetic congenital anomalies and can almost double the risk of neonatal and childhood death, mental retardation, and severe congenital anomalies following the union of first cousins or first siblings. In some minority communities, such as Ashkenazi Jews or Finns, the prevalence of rare genetic mutations is relatively high and the risk of congenital anomalies is also high.
Infections
Maternal infections such as syphilis and rubella are a notable cause of birth defects in low- and middle-income countries.
Maternal nutritional status
Disorders such as iodine deficiency, insufficient folic acid, obesity or diabetes are associated with certain congenital anomalies. For example, inadequate folic acid increases the risk of neural tube defects in infants.
Environmental factors
Maternal exposure to pesticides, drugs, alcohol, tobacco, other psychoactive substances, certain chemicals, high doses of vitamin A in early pregnancy, and high doses of radiation increase the risk of congenital anomalies in the embryo or infant. Working or living near or inside waste disposal sites, smelters or mines can also be a risk factor.
Prevention
The incidence of certain congenital anomalies can be reduced through public health precautions provided by preconception and periconceptional and prenatal health care services. Primary prevention of congenital anomalies includes
Improving a woman’s diet throughout her reproductive years to ensure adequate intake of vitamins and minerals, especially folic acid and iodine, through diet, and avoiding or limiting the intake of harmful substances, especially alcohol.
Controlling preconception and gestational diabetes through counseling, weight management, diet and, if necessary, insulin injections
Avoid exposure to harmful environmental substances (e.g., heavy metals, pesticides, certain drugs) during pregnancy.
Improve vaccination coverage for children and women, especially rubella virus vaccination. Rubella can be prevented by vaccination in childhood. Rubella vaccination can also be given to women who are not yet immune at least one month before pregnancy.
Increase and strengthen education for health personnel and others involved in promoting birth defects prevention.
Discovery
Preconception and periconceptional care includes basic reproductive health measures as well as medical genetic screening and counseling. Screening can be conducted during three phases.
Preconception screening is used to identify people who are at risk for a specific disease or who are at risk of passing the disease on to their children. Screening includes knowledge of family history and screening for carriers, which is particularly valuable in countries where consanguineous marriages are common.
Prenatal screening includes screening for advanced maternal age, Rh mismatch, screening for carriers, and screening for alcohol, tobacco, and other psychoactive substance use. Ultrasound can detect Down syndrome in early pregnancy and severe fetal abnormalities in mid-pregnancy; maternal serum screening can also be used to detect Down syndrome and neural tube defects in early and mid-pregnancy.
Newborn screening includes clinical examination and screening for blood, metabolic and hormonal disorders. Screening for deafness and heart defects and early detection of birth defects can help implement life-saving treatments and can prevent the development of certain physical, intellectual, visual or hearing disabilities.
Treatment and care
In countries with well-established health services, structural birth defects can be corrected with pediatric surgery and early treatment is available for children with functional problems such as thalassemia (an inherited recessive blood disorder), sickle cell disease and congenital hypothyroidism.
WHO’s response
In 2010, the World Health Assembly published a report on birth defects. The report describes the basic components of creating national plans for the prevention and care of birth defects before and after birth. The report also recommended priorities for the international community to assist in establishing and strengthening these national plans.
The Global Strategy for Women’s and Children’s Health, launched in 2010 by the United Nations in collaboration with heads of government and other organizations such as WHO and UNICEF, is essential for implementing high-impact and cost-effective interventions to improve newborn and child health.
WHO is also working with the National Center on Birth Defects and Developmental Disabilities, part of the U.S. Centers for Disease Control and Prevention, and other partners to establish a global policy for folic acid fortification at the country level and to provide the necessary expertise for monitoring neural tube defects, overseeing folic acid fortification efforts, and improving laboratory capacity on folic acid-preventable birth defects.
The International Birth Defects Surveillance and Research Information Exchange is a voluntary, non-profit, international organization formally affiliated with WHO. It brings together birth defects surveillance and research programs from around the world in order to investigate and prevent birth defects and mitigate the effects of their consequences.
The WHO Division of Reproductive Health and Research and the Division of Nutrition for Health and Development, in collaboration with the International Clearinghouse for Birth Defects Surveillance and Research and the National Center on Birth Defects and Developmental Disabilities, part of the U.S. Centers for Disease Control and Prevention, conduct annual workshops on surveillance and prevention of birth defects and preterm births. The WHO HIV and AIDS Division works with these partners to strengthen birth defects surveillance in women receiving antiretroviral drugs during pregnancy as part of national HIV planning monitoring and evaluation efforts.
The Global Alliance for Vaccines and Immunization, a WHO partner, is assisting developing countries to improve the control and elimination of rubella and congenital rubella syndrome through immunization.
WHO develops normative tools, including guidelines and global action plans, to strengthen medical and rehabilitation services to support implementation of the Convention on the Rights of Persons with Disabilities. Similarly, WHO supports countries to integrate medical and rehabilitation services into overall primary health care, supports the development of community-based rehabilitation planning, and promotes the strengthening of specialized rehabilitation centers and their linkages to community-based rehabilitation.