'Surprising' New Zealand/Sweden study shows premature girls stay shorter
Premature birth could be worse than famine for baby girls using one measure.
A study involving the University of Auckland's Liggins Institute shows girls born "very premature" grow into adults 2.3 centimetres shorter than their full-term counterparts.
Researchers from the institute and Sweden's Uppsala University analysed data from 200,000 Swedish women.
Women born "very premature" - before 32 weeks gestation - were three times more likely to grow into shorter adults than full-term, 37- to 41-week gestation babies.
Liggins Institute senior research fellow and lead study author Dr Jose Derraik said although the height difference "may not sound much", one of the world's worst man-made disasters put it into perspective.
"Women born during the great Chinese famine in 1959-1961, who experienced severe malnutrition early in life, were about 1.7cm shorter as adults," Derraik said.
"We were a little surprised by the results.
"There is some evidence that babies who were born premature tend to be shorter in childhood, but they usually catch up... our study shows woman who were born very pre-term fail to reach the stature you'd expect based on their parents' and siblings' heights."
The researchers, whose work was published in the American Journal of Epidemiology, said they had yet to prove why premature girls stayed shorter and could only speculate.
One study collaborator's previous research showed small birth size was connected with the way growth hormones worked.
Another Swedish study that analysed male military conscripts also showed a similar increase in shorter height risk for very premature male babies.
In 2014, 4421 New Zealand babies were born premature including 748 born less than 32 weeks of gestation.
New Zealand's percentage of premature births is 7.4 per cent of total births compared with an 11.1 per cent worldwide average.