A review of key terminology and definitions used for birth defects globally

Abstract

Birth defects, also known as congenital disorders, are a significant health issue impacting at least five million births annually worldwide. For policymakers to mount a relevant healthcare response to care for those affected, the burden of disease of these conditions must be quantified. Estimates of the contribution of birth defects to under-5 child mortality and morbidity are generated by several groups globally. These estimates often differ, causing confusion for policymakers. While some differences may be attributed to the data sources and methods used, much is due to a lack of clarity in the terminology used for the group of disorders classed as “congenital”. This study aimed to gain insight into the diversity of terms and definitions for birth defects, including those used routinely by relevant international/national organisations and in the peer-reviewed literature. This two-part study included (1) scoping review of peer-reviewed literature to identify terms and definitions in use for birth defects and (2) review of key websites and grey literature to identify terms and definitions used. The results of this study indicate a wide variety of terms being used, often interchangeably and undefined, in peer-reviewed publications, on institutional websites and related literature. This suggests a lack of clarity related to terminology and sets the scene for further discussion, recommending that the community of practice working on birth defects comes to a consensus on standard terminology and definitions for global uptake and implementation. Such standardisation will facilitate a common understanding of the burden of these disorders globally, regionally and within countries so that action can be taken to support affected children and their families.

Safety surveillance for PrEP in pregnant and breastfeeding women

“…Teratovigilance studies the exposure of the fetus to external factors (drugs, substances, environmental factors, etc) and any resultant foetal developmental abnormalities and their impact on public health using epidemiological approaches ( 55 ). Teratovigilance is not confined to structural malformation but includes effects such as fetal loss, preterm delivery, impaired fetal and infant growth and development ( 55 ).…”

“…Teratovigilance studies the exposure of the fetus to external factors (drugs, substances, environmental factors, etc) and any resultant foetal developmental abnormalities and their impact on public health using epidemiological approaches ( 55 ). Teratovigilance is not confined to structural malformation but includes effects such as fetal loss, preterm delivery, impaired fetal and infant growth and development ( 55 ). Often such studies are designed to assess the risk of specific teratogenic effects that may have a biological plausibility or hypothesis based on animal and human studies with the specific drug in question or from drugs in the same class.…”

Newborn screening in South Africa: the past, present, and plans for the future

“…Biochemical newborn screening (NBS) is a series of tests undertaken during the first hours or days of life to screen for congenital disorders (CDs). Some CDs, defined as abnormalities in structure or function present from birth, are immediately obvious, while others, such as many inborn errors of metabolism (IEM) and rare diseases, are not [1,2] . By the time some conditions manifest, ranging from hours, weeks, or months after birth, disease progression may already have caused irreversible damage, resulting in lifelong intellectual and other disabilities, or premature death [3] .…”

Action against birth defects: if not now, when?

“…The vast majority of newborns with a birth defect, including an estimated 94% of those with severe disorders, are born in low- and middle-income countries (LMICs) where diagnostic, treatment and management services are limited [ 3 ]. Absence of birth defects surveillance programs in most LMICs coupled with a lack of global consensus on birth defect terminology, means that we vastly underestimate the true burden of birth defects in these countries [ 5 ].…”