Short moms at higher risk of having premature baby: study

Melbourne: Short mothers are twice as likely to give birth to a premature baby than tall moms, a new study has claimed.

The odds of having a premature baby rises as the mother's height decreases, according to researchers from Uppsala University in Sweden and University of Auckland in New Zealand.

Among short mothers (155 centimetres tall or shorter), 9.4 per cent of babies were born premature (at less than 37 weeks of gestation), and 1.1 per cent very premature (less than 32 weeks of gestation), researchers said.

For tall mothers (179 centimetres or taller), these figures were 4.7 per cent and 0.5 per cent respectively, they said.

For the study, researchers examined data collected between 1991 and 2009 on more than 192,000 Swedish women aged over 18 years.

Premature birth is a major case of newborn death worldwide, and is linked to serious health problems in the short and long term.

"Around half of all premature births are 'spontaneous', apparently with complex and often unknown causes," said Jose Derraik from University of Auckland.

"Based on the mounting evidence, maternal height is one of the factors that needs to be considered when evaluating a woman's risk of delivering a premature baby," said Derraik.

The study adds to a body of evidence suggesting the shorter the mother, the higher the odds of giving birth early.

Researchers do not know exactly what is behind this association between the mothers' height and spontaneous premature birth, but evidence from other studies suggests it could be anatomical constraints, Derraik said.

"Short mothers tend to have less space for the babies to grow before birth, and this seems to lead to premature delivery in some women," he said.

The findings were published in the journal PLOS ONE.