Aim: To produce sex specific percentiles by gestational age for New Zealand infants.
Methods: Gestational age (completed weeks) and birthweight (10 g multiples) was obtained for all births in New Zealand in 1990 and 1991. Outliers were identified and removed, the data was normalised at each gestational age and percentiles produced.
Results: The percentile charts were produced for gestational ages 24 to 44 weeks by sex of infant. There was an approximate difference of 100 g between male and female birthweight at all gestational ages.
Discussion: These are the first national birthweight percentile charts for New Zealand. As they may vary over time we recommend they be updated every 5 years.