1.3 Surveillance

There are two main types of surveillance programmes often used for congenital anomalies surveillance. These are population-based and hospital-based programmes.

• Population-based surveillance programmes capture pregnancy outcomes of interest for the condition under surveillance, such as congenital anomalies, in a population living in a defined geographical area.
• Hospital-based surveillance programmes capture pregnancy outcomes of interest for the condition under surveillance, such as congenital anomalies that occur in selected hospitals in a well-defined location.

Countries with limited resources may choose to start with a hospital-based surveillance programme and expand it over time into a population-based programme. Population-based and hospital-based surveillance programmes are discussed in more detail in WHO/CDC/ICBDSR Birth defects surveillance: a manual for programme managers (4).

Possible response:

• Because there are few resources and 52% of births occur in hospital settings, it may be best to begin with a select number of large maternity hospitals. Once the hospital-based surveillance is well established, one can then begin to identify neonates with congenital anomalies born at home who are taken to hospitals or local clinics for services, to assess the possibility of implementing a population-based surveillance programme. If the country has community health workers and midwives who can cover home births and report to the surveillance programme, a population-based programme can be considered.

Possible response:

• Because most of the births in hospitals are to resident mothers, the programme would be considered a population-based surveillance programme. The programme could implement a way to capture the 5% of births from resident mothers that occur at home or at other facilities, which would help in the referral of children to services.