London, Feb 11: With an increasing number of women choosing to give birth when they’re in their late 30s or early 40s, a new study has scientists in the US warning that women who have a baby after they turn 40 are at an increased risk of stillbirth.

Scientists already know that conditions such as pre-eclampsia, problems with the position of the placenta which hamper natural delivery, and diabetes can increase the risk of stillbirth. Scientists carried out the study to find whether age is also a factor.

As a part of the research they looked at over 11 million babies born to women aged 15 to 44 between 1995 and 1997.

After excluding maternal complications and congenital abnormalities in the fetus, the researchers were then left with the medical histories of six million babies.

Based on the data from the US Centers for Disease Control, which registered the deaths of babies, the scientists found that women who give birth between the ages of 40 to 44 are at three times the risk of stillbirth than women aged 25 to 29.

Professor Mert Ozan Bahtiyar, of the department of obstetrics, gynecology and reproductive sciences at Yale University School of Medicine who led the study, recommended that the fetuses of older women should be monitored from 38 weeks onwards, with checks including listening to the baby's heart-beat and testing the amniotic fluid to pick up any signs of distress.

"Women expecting babies over 40 should be monitored from 38 weeks onwards. Any woman in that situation should not panic but, if they detect decreased foetal movement, they should contact their physician," the BBC quoted Bahtiyar, as saying.

The Yale University work is being presented to the Maternal-Fetal Medicine Conference being held in San Francisco. (ANI)