1.2 Congenital Anomalies
Expected time: 1.5 hours
According to WHO, an estimated 270 358 deaths globally were attributable to congenital anomalies during the first 28 days of life in 2012, with neural tube defects being one of the most serious and most common of these congenital anomalies.
The 63rd World Health Assembly in 2010 adopted a resolution on congenital anomalies (2), to encourage countries to build in-country capacity related to the development of congenital anomalies surveillance systems and the prevention of congenital anomalies, and to raise awareness about their impact. The resolution calls on Member States to prevent congenital anomalies wherever possible, implement screening programmes, and provide ongoing support and care to children with congenital anomalies and their families. WHO is to support Member States in implementing these services and to strengthen research and data collection in this area.
Structural congenital anomalies can be classified as one of two types: major anomalies or minor anomalies. Major and minor anomalies may sometimes be present in one individual.
- Major anomalies are structural changes that have significant medical, surgical, social or cosmetic consequences for the affected individual, and typically require medical intervention. Examples include spina bifida, anencephaly, heart defects and orofacial clefts. Major anomalies account for most of the mortality, morbidity, and disability related to congenital anomalies.
- Minor anomalies are structural changes that pose little or no significant health problem and tend to have limited social or cosmetic consequences for the affected individual. Minor anomalies are more common than major anomalies and can be a useful tool for clinicians to identify syndromes. Examples of minor anomalies include single palmar crease and clinodactyly (mild curvature of a finger).
Because the focus of Birth defects surveillance is a manual for programme managers (4) and this workshop is on major structural anomalies, the examples we will use throughout the course are major anomalies.
In the case of congenital anomalies, risk factors include:
- genetic factors;
- maternal conditions (e.g. diabetes and obesity);
- maternal age; and
- behaviours and environmental exposures that may put a woman at risk for having a pregnancy affected by a congenital anomaly.
- Nutritional deficiencies/insufficiencies (e.g. folate)
- Maternal age
- Maternal illnesses (e.g. diabetes, hypothyroidism)
- Infectious diseases (e.g. rubella, syphilis)
- Alcohol abuse
- Tobacco use
- Certain medications
- Environmental pollution (e.g. pesticides)
- Low socioeconomic status
- Genetic factors
- Have vaccinations up to date prior to pregnancy
- Maintain a healthy weight
- Consume adequate micronutrients, like folic acid, through fortified food products or vitamin supplements prior to pregnancy
- Control diabetes prior to pregnancy
- Use iodine to prevent hypothyroidism
- Abstain from alcohol abuse or smoking prior to, and during, pregnancy
- Speak with a health-care provider about any medication use
- World Health Organization. Congenital anomalies. Fact sheet No 370. October 2012 (http://www.who.int/mediacentre/factsheets/fs370/en/index.htmlExternal, accessed 29 April 2015).
- Resolution WHA63.17. Birth defects. In: Sixty-third World Health Assembly, Geneva,17–21 May 2010. Geneva: World Health Organization; 2010 (http://apps.who.int/gb/ebwha/pdf_files/WHA63/A63_R17-en.pdfCdc-pdfExternal, accessed 29 April 2015).
- International statistical classification of diseases and related health problems, 10th revision. Geneva: World Health organization; 2015 (http://apps.who.int/classifications/icd10/browse/2015/enExternal, accessed 24 February 2015).
- World Health Organization, National Center on Birth Defects and Developmental Disabilities from the United States Centers for Disease Control and Prevention (CDC), International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR). Birth defects surveillance: a manual for programme managers. Geneva: World Health Organization; 2014 (https://www.cdc.gov/ncbddd/birthdefectscount/documents/bd-surveillance-manual.pdfCdc-pdf, accessed 10 February 2015).
- World Health Organization, National Center on Birth Defects and Developmental Disabilities from the United States Centers for Disease Control and Prevention(CDC), International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR). Birth defects surveillance: atlas of selected congenital anomalies. Geneva: World Health Organization; 2014 (http://apps.who.int/iris/bitstream/10665/127941/1/9789241564762_eng.pdf?ua=1Cdc-pdfExternal, accessed 10 February 2015).
- CDC Foundation. What is public health? (http://www.cdcfoundation.org/content/what-public-healthExternal, accessed 24 February 2015).