A groundbreaking study by Murdoch Children's Research Institute has shown unequivocally for the first time that the environment experienced in the womb may have a greater effect on our future health than previously thought - and more of an effect than our DNA and the health and lifestyle of our mothers while pregnant.
Researchers studied 22 identical twin pairs and 12 non-identical twin pairs and mapped their epigenetic markers - which are 'above' the genes and tell the genes to switch on and off. By comparing the level of epigenetic differences in identical twins versus non-identical twins, researchers were able to estimate the contributions of both genes and environment in the womb to the newborn epigenetic profile.
The study, which was published inGenome Research, focused on the time spent in the womb and examined placenta, umbilical cords and cord bloods collected at birth.
Researchers Drs Jeff Craig and Richard Saffery, from Murdoch Children's said the study showed for the first time on a genome-wide scale that identical twins, which share the same DNA sequence, can have different epigenetics at birth, which further highlights the importance of the intrauterine environment in shaping the neonatal epigenome.
"This study demonstrated that the unique environment in the womb plays a critical role in setting up this epigenetic profile. This must be due to events that happened to one twin and not the other whilst in the womb and shows that the experiences in the womb are important in defining the epigenetic profile we are born with," Jeff said.
The research has potentially wide-ranging implications for human health given that many adult onset diseases are thought to develop very early in life.
"Importantly, this has potential to identify and track disease risk early in life or even to modify risk through specific environment or dietary intervention. Knowing the result for each of us at birth could help predict and better manage our future health."
Researchers say these ideas are further supported by their finding that birth weight differences within pairs of twins are related to epigenetic differences, especially in genes that may be linked with predisposition to diseases previously associated with low birth weight.