Studies reported at the annual meeting of the Society for the Study of Reproduction in July in Pittsburgh demonstrate that maternal nutrition, protein intake and level of fat in the diet may cause changes in the developing foetus that can have long-term health consequences.
The time between ovulation and conception may be a critical one for maternal and foetal health, according to Dr Kelle Moley of the Washington University School of Medicine. In mouse studies, she found that subtle differences in maternal meta-bolism had long-lasting effects. Indeed, when Dr Moley transferred embryos from a diabetic mouse into a non-diabetic mouse shortly after egg implantation, she noted neural tube defects, heart defects, limb deformities and growth defects in offspring. These findings indicate that we
may need to redirect our ideas about maternal health to the time prior to pregnancy.
According to Dr Kevin Sinclair of the University of Nottingham, maternal nutrition even at the time of conception can alter foetal development. In studies with sheep and rodents, he found that offspring of mothers with vitamin B12 and folic acid deficiencies were fatter, became insulin resistant and had higher blood pressure by the time they reached middle-age, demonstrating that early molecular changes may not manifest themselves for many years. So vitamin supplementation before conception may be more important than after.
Dr Tom Fleming of the University of Southampton reported that low protein levels in female mice during the first few moments of conception, when the egg is still dividing, caused abnormal growth, cardiovascular disease, high blood pressure and jumpy behaviour in their offspring. Mice born to mothers with low protein grew bigger – extracting as many nutrients as they could to compensate for poor nutrition while in the womb.
Dr Shuk-mei Ho of the University of Cincinnati Medical Center explained that, according to epigenetic theory, changes in the genome can happen at any time through the impact of environmental factors on the expression of genes over time. One of the most critical periods is early life when epigenetic memories are created that may impact a person's susceptibility to disease later in life. These ‘memories’ may remain dormant until an environmental trigger brings them to the surface, modifying risk for disease.
First Published in October 2009
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