Slim mothers may be impacting the liver health of their babies in later life, say UK researchers.
Their findings add to the importance of improving a mother's nutrition before she conceives to protect against disease in later life.
There is an increasing body of evidence to suggest that growth from the very earliest days in the womb affects health in adulthood, particularly the risks of heart disease, diabetes and osteoporosis.
Now, a team from the universities of Southampton, Bergen and Oslo say that they have found a link between mothers eating an unbalanced diet and an increased amount of blood flowing to the foetal liver.
While this 'liver-sparing' pattern of blood flow is thought to protect the foetus from a nutrient deficit, the researchers believe it may also affect liver function in later life, increasing the risk of adult heart disease and diabetes in the offspring.
"This research is the first work to recognise that a mother's slimness and diet alter the circulation of blood in her developing baby in the womb," said study leader Dr Keith Godfrey, a scientist in the Medical Research Council (MRC) Epidemiology Resource Centre at the University of Southampton.
"As a mother's slimness and unbalanced diet during pregnancy have been linked with susceptibility to heart disease and diabetes in the offspring in later life, the findings may have important implications."
The researchers studied a group of 381 healthy babies whose mothers are part of a large project studying nutrition before and during the pregnancy of more than 2,000 women (the Southampton Women's Survey).
They used new ultrasound technology to measure blood flow to the liver of the developing baby late in pregnancy.
Their results, published in this month's issue of the American journal Circulation Research (96:12), suggest that the babies of slimmer mothers with lower body fat stores and those eating an unbalanced diet have greater liver blood flow and divert less blood away from the liver in late pregnancy.
This change in blood flow may cause subtle changes in the development of the liver and alter the baby's ability to cope with a high-fat 'Western' diet in later life, thereby predisposing to adult heart disease and diabetes, they explain.
By measuring the growth and development of the babies during the pre-school years, the researchers hope to identify whether or not the liver blood flow adaptations in the womb have long-term implications.
"The observations suggest that before birth many normal babies adapt to the supply of nutrients from the mother and alter the amount of blood flowing to the liver. We believe that this 'liver-sparing' adaptation could help the baby to continue growing in the womb, even if the mother's body is not able to supply the nutrients needed by the baby."
"However, the adaptations could have long-term consequences for how the liver deals with fat and other nutrients after birth," said Dr Godfrey.