Men who become fathers at an older age and / or consume large amounts of alcohol may face taking care of a child with birth defects.

This finding is according to a growing body of research uncovered by researchers at Georgetown University Medical Centre.

They say these defects result from genetic alterations that can potentially affect multiple generations.

The study suggest both parents contribute to the health status of their offspring – a commonsense conclusion which science is only now beginning to demonstrate, says the study’s senior investigator, Joanna Kitlinska, PhD, an associate professor in biochemistry and molecular and cellular biology.

“We know the nutritional, hormonal and psychological environment provided by the mother permanently alters organ structure, cellular response and gene expression in her offspring,” she said.

She added that “our study shows the same thing to be true with fathers – his lifestyle and how old he is can be reflected in molecules that control gene function. In this way, a father can affect not only his immediate offspring but future generations as well.”

For example, a newborn can be diagnosed with fetal alcohol spectrum disorder (FASD), even though the mother has never consumed alcohol, said Kitlinska.

“Up to 75% of children with FASD have biological fathers who are alcoholics, suggesting that pre-conceptual paternal alcohol consumption negatively impacts their offspring.”

The report is a review of evidence, human and animal, published to date on the link between fathers and heritable epigenetic programming.

Among the studies reviewed are ones that find:

• Advanced age of a father is correlated with elevated rates of schizophrenia, autism and birth defects in his children;
• A limited diet during a father’s pre-adolescence has been linked to reduced risk of cardiovascular death in his children and grandchildren;
• Paternal obesity is linked to enlarged fat cells, changes in metabolic regulation, diabetes, obesity and development of brain cancer;
• Psychosocial stress on the father is linked to defective behavioural traits in his offspring and
• Paternal alcohol use leads to decreased newborn birth weight, marked reduction in overall brain size and impaired cognitive function.

“This new field of inherited paternal epigenetics needs to be organized into clinically applicable recommendations and lifestyle alternations,” said Kitlinska.

“And to really understand the epigenetic influences of a child, we need to study the interplay between maternal and paternal effects, as opposed to considering each in isolation.”

And on the flip side, another study shows that a relatively healthy diet before pregnancy is linked to a lower rate of certain heart abnormalities in babies at birth.

Congenital heart defects are common, costly and affect around 1% of newborns in the U.S. Around one in four affected children will die infancy as a result. So far, doctors have few preventive options at their fingertips.

Some studies suggest that multivitamin supplements might lower the risk while others suggest that better diet quality might make a difference to the rate of heart abnormalities at birth.

In a bid to find out about the potential role of diet, the researchers quizzed around 19,000 women about the quantity and quality of their diet in the year leading up to their pregnancy.

The women were all part of the National Birth Defects Prevention Study. Half had given birth to healthy babies and half had had babies with major heart abnormalities at birth between 1997 and 2009.

Diet quality was assessed, using two validated scoring systems: the Mediterranean Diet Score and the Diet Quality Index for Pregnancy (DQI-P).

Moms in the top 25% (quartile) of diet quality, as assessed by the DQI-P, had a significantly lower risk of having a baby with certain heart defects than those in the bottom 25%.

Better diet was associated with a 37% lower risk of tetralogy of Fallot and a 23% lower risk of atrial septal defects.

Atrial septal defects refer to holes in the wall of the septum, which divides the upper chambers (atria) of the heart. Tetralogy of Fallot is a complex abnormality which can lead to dangerously low oxygen levels in the blood going to the rest of the body.

This is an observational study so no definitive conclusions about cause and effect can be drawn, but similar associations have been found for diet before pregnancy and some other birth defects, including cleft palate and neural tube defects, note the researchers.

And they conclude that a reduced risk of some congenital heart defects may be an added bonus of eating a healthier diet before pregnancy, which reinforces current dietary recommendations for women wanting to get pregnant.