3.5 Case Inclusion
- Major anomalies
- External major anomalies (e.g. neural tube defects)
- Internal major anomalies (e.g. heart defects)
- Minor anomalies
- External minor anomalies (e.g. pre-auricular tags)
- Both major and minor anomalies
- Availability of technology
- Availability of specialists
- Capacity to diagnose
- Complexity of the anomaly
- Ability to prevent the congenital anomaly
- Availability of evidence-based prevention strategies
- Ability to collect high-quality data
- Ability to monitor prevention interventions
- Ability to show public health impact
Provide the following considerations to the participants to help guide the discussion.
- Feasibility of prevention
- Are there available evidence-based prevention strategies?
- Can surveillance data assist in evaluating prevention strategies?
- Availability of staff and staff capacity
- Are there sufficient staff to conduct surveillance?
- Is training available for surveillance staff?
- Availability of testing
- Are special tests necessary to confirm the diagnosis, for example karyotype?
- Availability of equipment
- Is there equipment available that is necessary to diagnose internal anomalies, for example sonograms, X-rays and echocardiograms?
- Availability of specialists
- Are there specialists available in the country to make diagnoses?
- Are there funds available for surveillance?
Some surveillance systems may not be appropriate for certain congenital anomalies. For example, those congenital anomalies typically identified after the neonatal period may not be captured in hospital-based systems unless there are resources to include children after discharge from the birth hospital. If a surveillance programme is specifically designed to evaluate a public health intervention such as folic acid fortification, then the priority may be to measure the related birth outcomes – for example, neural tube defects – as opposed to other unrelated anomalies.
Incremental costs should be considered. If no extra costs would result from monitoring other anomalies in addition to neural tube defects, consider collecting data on other types of congenital anomalies. Including more congenital anomalies in the surveillance programme will probably require additional resources.
When starting a new congenital anomalies surveillance programme, consider starting with a small number of easily recognizable major external congenital anomalies with intervention or prevention potential and then expand to include additional congenital anomalies as the programme gains experience, creates awareness in participating facilities, and obtains more resources.
The list of anomalies will vary, depending on capacity and resources, but typically includes major external anomalies, for example orofacial clefts, neural tube defects and limb deficiencies.
Detecting many internal structural anomalies, such as unilateral kidney agenesis, requires imaging techniques or other procedures that may not be readily available. Additionally, even using the most advanced imaging techniques, the diagnosis of some internal structural anomalies, such as some congenital heart defects, can be very difficult.