There's now overwhelming evidence that a child's future health is influenced by more than just their parents' genetic material, and that children born of unhealthy parents will already be pre-programmed for greater risk of poor health, according to researchers. "The reality is, the child doesn't quite start from scratch -- they already carry over a legacy of factors from their parents' experiences that can shape development in the fetus and after birth. Depending on the situation, we can give our children a burden before they've even started life," experts say.
At fertilization, the gametes endow the embryo with a genomic blueprint, the integrity of which is affected by the age and environmental exposures of both parents. Recent studies reveal that parental history and experiences also exert effects through epigenomic information not contained in the DNA sequence, including variations in sperm and oocyte cytosine methylation and chromatin patterning, noncoding RNAs, and mitochondria. Transgenerational epigenetic effects interact with conditions at conception to program the developmental trajectory of the embryo and fetus, ultimately affecting the lifetime health of the child. These insights compel us to revise generally held notions to accommodate the prospect that biological parenting commences well before birth, even prior to conception.