Is Father Equally Responsible For Baby's Health?

Lots of health videos circulate on social media, but one of the topic that grabbed attention of many is how man's sperm can affect not just the child's genes, but a mother's pregnancy experience. Dr Kirtly Jones, who has also been featured in the podcast of Health, University of Utah gives insight to how men influence pregnancy and what can to do to prepare for a healthy pregnancy of their partners.

Over the last two decades, researchers have discovered some fascinating insights on how genes can be influenced very early in the development. It could be as early as after fertilization. This is even before the woman herself realizes that she is pregnancy. This is a crucial time for the embryo and it can switch genes on or off to alter the way they function. This is also known as epigenetics. This does not change the DNA, however, it does modify how genes are expressed, and determines how they produce proteins and lastly, how it functions. These changes could continue throughout pregnancy and well into early childhood.

Role of the sperm

Historically and conventionally, the role of men in reproduction was believed to be limited to providing genetic material through sperm. This was thought as a simple delivery of DNA to the egg. However, there have been research that prove that this is more complex than thought.

Turns out, that genes in sperm can also be influenced by the environment in which they develop inside the man. These environmental modifications to sperm could also carry over and affect the development of the child.

In a 2013 study, published in the Journal of Neuroscience, it was studied how stress in male mice impacts their offspring. The researchers were able to see that stressed mouse dads experienced changes in their sperm and their offspring also exhibited abnormal stress. This was different when the offspring were compared to those of non-stressed dads.

For a mouse, it takes around 42 days to produce sperm and it was during this period when the mouse dads were exposed to stressors. This involved smell of foxes, wet bedding, brief restriction in a tube, and unfamiliar noises. Although DNA of the stressed dads' sperm was identical to that of the non-stressed mouse dad, the way it was processed was totally different.

These changes in sperm epigenetics is what led to stress responses abnormalities in the offspring as adults.

Now, talking about the human dads, or dads-to-be, precisely, the evidence that a father's health and behavior can also affect their sperm could be seen. A study that examined the cord blood of babies born to obese men revealed changes in how a particular gene regulating growth and calorie was expressed.

Wait, there's more!

What men eat could also impact how a mother feels during pregnancy.

While women are asked to not drink and smoke during pregnancy because it may impact the baby's health, it is also because babies are literally connected to mothers. But does dad's behavior matter too?

A fetus is physically connected to its mother, and factors like her physical and mental health, exposure to toxins, and nutrition have long been acknowledged as key to a newborn’s fitness. Yet the father’s role in ensuring a healthy pregnancy is often overlooked. That’s unfortunate because growing evidence suggests that fathers play a much more significant role than previously thought.

What’s more, this responsibility doesn’t just begin at conception. Both parents’ health and lifestyle choices before trying to conceive can profoundly influence their baby’s health.

How does it influence pregnancy and child's health?

Sperm plays a vital role in the formation of the placenta, a structure crucial to fetal development. Impaired sperm has been linked to higher miscarriage rates, likely because damaged sperm contains elevated levels of harmful free radicals.

There have been studies that proved that sperm can carry "biological memories" of environmental and lifestyle factors that influence gene expression. These epigenetic changes don’t alter the DNA itself but affect how genes function, leaving chemical marks on them. Alarmingly, these modifications can be passed down to future generations.

In rodent studies, exposure to certain endocrine disruptors caused epigenetic changes in sperm that were transmitted to over 90% of male descendants for up to three generations. This process, known as transgenerational epigenetic inheritance, highlights how a father’s environment and habits can have far-reaching consequences.