A person's risk of developing heart disease could be affected by experiences including anaemia before birth, researchers have found.
Fetal anaemia, or rhesus disease, was a leading cause of baby deaths until New Zealand doctors developed a procedure to give transfusions to babies still in the womb.
A study of 95 New Zealanders who have undergone this treatment since it was developed in 1963 has found they had differences in their hearts and blood vessels as an adult that were not present in those who did not have the treatment.
University of Auckland Liggins Institute researchers compared the heart development of those who were treated with a sibling who was unaffected by the disease.
Those who underwent the transplant had smaller hearts with thicker-walled heart chambers, as well as lower levels of HDL "good" cholesterol which protects from heart disease.
But it's too soon to say whether it will affect their chances of getting heart disease with participants who are still aged 18 to 47, younger than the age at which heart disease usually appears.
"We can't say whether the changes we saw will result in increased rates of heart disease when these people get older," researcher Dr Alexandra Wallace said.
"They might have more heart disease as a group, or earlier onset of heart disease, or there may be no difference - their bodies might have managed to cope with and adapt to these differences."
Medical advances mean it's now possible to prevent the disease, but up to seven babies a year in New Zealand still receive blood transfusions in the womb.