Women planning to give birth have a further reason to keep fit after research found that the bigger the mother, the bigger their baby.
A study of more than 500,000 pregnant women published in The Lancet yesterday found that for every kilogram a woman put on during pregnancy, her baby gained 7.35 grams.
Babies born to women who gained more than 24 kilograms during pregnancy were about 150 grams heavier at birth than those of women who gained 8-10 kilograms.
Women who gained more than 24 kilograms during pregnancy were more than twice as likely to give birth to a child weighing four kilograms or more compared with women who gained 8-10 kilograms.
While big babies have long been associated with good health, the research concluded that high birth weight could lead to a higher risk of obesity later in life and other diseases such as asthma and cancer.
Dr Penelope Sheehan, an obstetrician at the Royal Women's Hospital's Pregnancy Research Centre, said babies in the 95th percentile (those weighing more than four kilograms) were also at higher risk of getting stuck during delivery and injuring the mother.
She said large babies born to overweight women also carried a higher risk of jaundice and low blood-sugar levels after birth because of the mothers' higher-than-usual intake of sugar during pregnancy.
''The pre-pregnancy weight of a mother is significant, and this study shows that the pregnancy weight is also significant,'' she said. ''Anything women can do to stay fit and healthy before having a baby is going to be good for them and their baby.''
Source: The Age