When a woman becomes pregnant or begins to plan to become pregnant, she is encouraged to adopt or continue healthy habits in order to give her developing baby the best chance for a healthy future. She is told to eat certain foods, avoid some medications, drugs, and alcohol, and get enough sleep and exercise.

She is often prescribed prenatal vitamins to ensure that the newborn gets important nutrients. But what if health habits and lifestyles of both fathers and mothers have an impact on the future health of their offspring before they even conceive a child? What if responsibility for the health of potential infants starts before conception?

Both parents’ health habits, before they even plan to become parents, can impact their children’s and grandchildren’s health.

Our understanding of prenatal care and nutrition has expanded to include consideration of environmental and psychological influences that can affect the health of the parents' cells long before pregnancy is considered — or even possible. A recent study by Australian researchers discusses the growing awareness that parenting begins before conception.

Research has shown that eggs and sperm, before they combine to begin the process of fetal development, can undergo alterations in their genetic potential as a result of being exposed to certain chemicals or events.

These Epigenetic can influence any of the cells in the body, and they can be passed on so their influence can be profound and long-lasting.

While the actual building blocks of the DNA do not change, the genes that are present can be turned on and off by biochemical changes called methylation.

These changes impact the way the genes express themselves when a fetus develops. This in turn influences the lifelong health and well being of the child into adulthood. It can even change the way disease patterns are inherited by subsequent generations.

In other words, both parents’ health habits, before they even plan to become parents, can impact their children’s and grandchildren’s health.

Research suggests that the physiologic environments in which eggs and sperm develop can have an effect on their genetic material, influencing how genetic signals for future traits may get turned on and off. One way this occurs is via the egg’s and sperm’s environments.

While the mother’s responsibility to her fetus has long been accepted, the role of the father’s health before and around the time of conception has been underestimated.

A woman’s egg cells are suspended in fluid that has a special nutritional environment that reflects the mother’s own physiologic state of healthfulness. As the egg matures, this surrounding environment influences the egg's DNA (genetic coding). Similarly, the sperm is affected by the characteristics of the male’s seminal fluid that bathes it.

Exposures, such as to environmental chemicals like the endocrine disruptor bisphenol A, can cause lasting changes that may lead to cancers or other chronic health problems.

When future parents drink, smoke, are poorly nourished or obese, they may be affecting the genetics of their eggs and sperm. When the eggs and sperm combine to develop into a fetus, the response of their DNA may reflect these earliest exposures.

Researchers are exploring the idea that offspring characteristics such as anxiety, immune dysfunction and a higher risk of metabolic diseases such as diabetes and cardiovascular disease are among the many possible outcomes altered by this process.

The new study, published in Science, describes what this important new understanding means for the role of parents. According to the authors future parents can make some healthy choices and avoid toxic exposures for the benefit of their children.

They further stress that while the mother’s responsibility to her fetus has long been accepted, the role of the father’s health before and around the time of conception has been underestimated.

Couples who are beginning to plan their families may wish to consult their health care providers on steps they can take in pre- and periconception planning to give their children their best start. Common sense approaches for healthy lifestyles of both parents —such as avoiding smoking, drinking, drugs, nutritional extremes, and toxic exposures — are a good start.