How your mum ruined your life before you were even born.

It’s all our fault. AGAIN.

We mums get the blame for everything, don’t we? But this time even science says so.

A raft of studies have now been conducted backing up the theory that a mother’s (and, on occasion father’s) behaviour both pre-conception, and while pregnant has a lasting impact on your outcomes for the rest of your life.

Oh the guilt.

According to the experts everything from what we eat to the air we breathe can impact upon our unborn babies.

Luckily most of us mums are pretty used to guilt so we will just add this to a long, long list of things-to-feel-guilty-about-today and do our best at harm minimisation.

We all know about the big ones that our doctors warn us against – no drinking, no smoking and no soft cheeses, but there are a whole host of other factors that can change the life course of our unborn babies.

A paper from Princeton University has found that “the nine months spent in utero is increasingly recognised as a critical period that affects a person's health and economic outcomes over the entire life course. Indicators of health at birth such as birth weight have been found to predict future outcomes including earnings, employment, education and the health of the next generation.”

Stress:

Researchers have found that a mother’s emotional state during pregnancy can affect the development of her baby’s brain.

Called “fetal programming” -where a changing environment in the womb through different sensitive periods- alters the development of the fetus.

One explanation is that the fetus is exposed to increased amounts of the stress hormone, cortisol when a mother-to-be goes through stressful periods. Exposure to raised cortisol levels in the amniotic fluid is associated with lower cognitive function in the child later on.

Watch how stress during pregnancy can impact their child later in life. (Post continues after video.)

Research has also shown that if your mother was stressed while she was pregnant with you it will affect your verbal IQ, making it drop by about half a standard deviation. And the list goes on, stress can even affect an unborn baby's co-o-ordination with new research from West Australia finding that children with the poorest motor function were born to mothers who had recorded three or more stressful events during pregnancy.

Weight:

We all know the importance of following a healthy diet and taking the right vitamins during pregnancy.

Science has now shown us that in fact a mother’s diet pre-conception is more important to her unborn baby than her diet while she is pregnant.

Researchers from Northwestern University in Illinois found that while pregnant a mother’s body “buffered" the supply of nutrients to their unborn babies, meaning that fetuses were partly protected from changes in women's diets.

Far more important was the diet of a woman when she was a child.

What does impact upon on unborn baby though is the weight of her mother.

Both seriously overweight and underweight women can cause longer-term problems for their unborn babies.

Underweight mothers can lead to a risk of their baby being born at a low-birth weight, which is associated with a range of adverse outcomes in childhood and later in life.

Maternal obesity also increases the risk of a woman developing gestational diabetes or going into preterm labor, and then there are the increased risks of diabetes in the child. Recent studies have also linked a woman's pre-pregnancy weight to her child's risk of asthma.

Smoking:

We all know the dangers of smoking but new research suggests that even exposure to secondhand smoke in the womb may lead to health problems later on.

One study of mothers and children in China found that kids born to mothers exposed to secondhand smoke during pregnancy were more than twice as likely to develop attention and aggression problems by the age of five than the children of mothers unexposed to smoke.

Sunshine:

Yep this too.

Researchers at the University of Calgary have found that low levels of vitamin D in pregnancy can mean an increased risk of gestational diabetes, pre-eclampsia and lower birth weight.

Sickness:

Even catching the flu during pregnancy can lead to adverse outcomes for your baby- and this time not just for their health – but for their wallet.

A study by Princeton University looked at patterns of seasonal influenza and found that infants who suffer in utero exposure to maternal influenza infections earn 10% less than siblings who were not exposed.

Where you live:

Breathing outdoor air pollution caused by traffic, industry and even dust during pregnancy may slightly increase the risk that a baby will be born at a lower birth weight.

Makes you want to lock yourself in a glassed room for nine months doesn't it?

It’s not ALL our fault though, just to balance out the guilt we can throw a little shade Dad’s way. Researchers say that a man’s sperm carries a memory of his environment and possibly even his diet and other lifestyle choices too through the epigenome, a network of chemical compounds surrounding DNA.

Have I made you feel bad enough? I hope not – because the fact is that in the majority of these studies the sample sizes looked at the average impact over large groups of people, and may very well not describe your individual case.

Phew. We’re off the hook aren’t we?