New father raises birth risk: study

Women whose second child is fathered by a different man than the first have double the risk of a having a pre-term or small baby, Norwegian researchers say.

In what is thought to be the first study looking into the impact of switching partners between the first two births, scientists at the Norwegian University of Science and Technology, in Trondheim, found it could influence the pregnancy and birth.

"Low birthweight, pre-term birth and infant deaths were significantly higher among women who had changed partners from the first to the second birth, compared to women who had the same partner for both children," Professor Lars Vatten, of the University of Science and Technology, said.



Professor Vatten and his colleagues, who studied data from the Norwegian birth registry of nearly 500,000 women over 30 years, said they did not know why there was an increased risk of a pre-term birth, but believe lifestyle could be involved.

"We speculate that women who change partners may have a different lifestyle from women who have the same partner for a first and second child," Professor Vatten said.

They could be more likely to smoke and drink alcohol during the pregnancy and could have poorer nutrition, which could affect the unborn child.

The study covered 30 years from 1967, when about 3 per cent of women in the study had two children fathered by different men, to the end of 1998, when the percentage had risen to about 10 per cent.

"It has to do with divorce and societal changes," Professor Vatten said. "People tend to get divorced much more often now than before and women have children with different partners because of that."

Premature and low-birthweight babies have a higher chance of developing respiratory problems and other medical complications because of their size and underdeveloped lungs. Studies have also shown they have a higher risk of heart disease as they grow older.

- REUTERS