Blood test on newborns could prevent disability, say scientists

A blood test to assess the risk of brain damage in vulnerable newborn babies could save lives and prevent disability, scientists say.

The test, carried out on blood taken from the umbilical cord immediately after birth, measures its acidity (the pH level). Blood with a low pH (more acid) indicates a lack of oxygen at birth, which is the commonest cause of brain damage, cerebral palsy and death.

Current guidelines suggest that measuring the pH level of umbilical cord blood is worthless as a predictor of how the baby will fare, because the association is inconsistent. But doctors based in Birmingham reviewed 51 studies involving almost 500,000 babies and found a low pH in the cord blood was strongly linked with serious outcomes.

Based on their findings, published in the British Medical Journal, they call for increased surveillance of babies born with low cord blood pH and for further research to explore the cost effectivenees of doing the test on all babies.

In an accompanying editorial, James Neilson, professor of obstetrics and gynaecology at the University of Liverpool, said: "We should aim to reduce the number of babies born with a low cord pH, without increasing unnecessary obstetric intervention."

Andy Shennan, professor of obstetrics at St Thomas' Hospital in London welcomed the study into the relationship between low pH and future health. "Lack of oxygen to the baby during labour will result in a low pH in the umbilical cord," he said. "If it is prolonged, irreversible neurological damage can occur, although this is rare."