Background: There is currently no published information on the full range of morbid conditions affecting mothers and newborns in Australia. Hospital morbidity data collections are a possible source of this information, but have not been widely utilised due to concerns about data quality.

Aims: To assess the accuracy and reliability of perinatal morbidity reporting to the New South Wales Inpatient Statistics Collection (NSW ISC).

Methods: A sample of 1000 records relating to 500 mothers and 500 newborns were randomly selected from the NSW ISC for the financial year 1999-2000 and compared with information obtained from medical records. Sensitivities and specificities were calculated for conditions of clinical relevance.

Results: There was a wide range of sensitivities among the 41 conditions selected, indicating a variable level of under-enumeration. Only 17 (41%) had a sensitivity of 80% or more. Sensitivities were more than 95% for gestational diabetes, prolonged pregnancy, perineal laceration, single live birth, low birth weight, and intracranial haemorrhage. However, numbers are small and confidence intervals wide for some of these conditions. Specificities were generally high. Neonatal conditions tended to be more accurately reported than maternal conditions. The pattern of results was similar to that reported for state perinatal data collections.

Conclusions: While hospital administrative data are readily available, data quality is a valid concern. However, if the data are viewed critically and information on accuracy is available, they can be a useful resource for monitoring the health of mothers and babies.