Age at diagnosis of birth defects

Area of Science:

• Public Health
• Epidemiology
• Pediatrics

Background:

• Birth defect surveillance programs often limit case ascertainment to diagnoses made within the first year of life.
• The Western Australian (WA) Birth Defects Registry extends ascertainment up to six years of age, but the value of this extended period is unquantified.

Purpose of the Study:

• To evaluate the contribution of diagnoses made between one and six years of age to the overall ascertainment of birth defects in Western Australia.
• To assess the workload associated with extended ascertainment beyond one year.

Main Methods:

• Analysis of all birth defect cases notified to the WA Birth Defects Registry for births and terminations of pregnancy in 2000-2001.
• Estimation of the person-time required for ascertainment of cases diagnosed between one and six years of age.

Main Results:

• Out of 3294 cases, 12.1% (400 cases) were first diagnosed between one and six years of age.
• Conditions like Fetal Alcohol Syndrome (two-thirds diagnosed after one year) and congenital hearing loss (one-quarter diagnosed after one year) significantly contribute to later diagnoses.
• Ascertaining cases diagnosed between one and six years required an estimated 1.76 person-weeks of work annually.

Conclusions:

• Approximately one in eight birth defect cases are identified beyond the first year of life.
• The increased completeness of birth defect data justifies the modest additional resources needed for extended ascertainment in Western Australia.