A baby's development in the womb in the first weeks of life is critical for future heart health, research suggests.

A link between poor growth in the first trimester and early risk factors for heart disease has been identified for the first time.

The study, in the British Medical Journal, adds to evidence that heart risk is set long before adulthood.

Pregnant women should think about their baby's heart health as well as their own, the British Heart Foundation said.

The evidence comes from a study tracking the health, from early pregnancy onwards, of nearly 2,000 children born in the Dutch city of Rotterdam.

A team at the Erasmus University Medical School examined links between the child's size at the first scan (10 to 13 weeks) and markers of future cardiovascular health at the age of six (central body fat, high blood pressure, high insulin levels and high cholesterol).

"Impaired first trimester foetal growth is associated with an adverse cardiovascular risk profile in school age children," they reported in the British Medical Journal.

"Early foetal life may be a critical period for cardiovascular health in later life."

Low birth weight is known to be linked to an increased risk of heart disease in later life. But the new research suggests not only birth weight but poor growth in the earliest phase of pregnancy may influence cardiovascular disease risk.

"These results suggest that the first trimester of pregnancy may be a critical period for development of offspring cardiovascular risk factors in later life," study author Prof Vincent Jaddoe told BBC News.

"Therefore adverse maternal lifestyle habits influencing early foetal growth may have persistent consequences for their offspring, many decades later. "

This was the first study showing this link and replication in other studies was needed, he added.

Critical stage

Amy Thompson, senior cardiac nurse at the British Heart Foundation, said the first few months of pregnancy were a critical stage in a baby's development.

"This study suggests that foetal growth within this time may influence their heart health later in life," she said.

"However, as the researchers acknowledge themselves, further studies are needed to understand why this pattern exists and what it might mean for preventing heart disease.

"If you are pregnant, or planning a family, you should be thinking about your baby's heart health as well as your own," she added.

"If you smoke, speak to your GP or midwife about quitting, and keep a check on your blood pressure.

"Your midwife will also advise you on other ways you can make healthier choices during pregnancy."