New research by the University of Otago shows inaccuracies are being made in height and weight measurements of pregnant women at their 12-week scan, which could have implications for their care.
Published today in the New Zealand Medical Journal, the recorded heights and weights differed from the women's actual measurements.
Of the 248 women studied, 69% had an under-reported body mass index (BMI), 25% an over-reported BMI, while 6% were correct.
As a result, 17% would have had an incorrectly classified BMI. Height and weight are used to assess risks in pregnancy and labour for both mother and baby.
Researcher and consultant obstetrician and gynaecologist Dr Helen Paterson said that lead maternity carers needed to have access to accurate scales.
''It's a concern that along with an increasing problem with excess weight and obesity in New Zealand, we have unreliable height and weight data on which to make clinical decisions,'' Dr Paterson said.